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Klunk CL, Heethoff M, Hammel JU, Gorb SN, Krings W. Mechanical and elemental characterization of ant mandibles: consequences for bite mechanics. Interface Focus 2024; 14:20230056. [PMID: 38618235 PMCID: PMC11008963 DOI: 10.1098/rsfs.2023.0056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 02/16/2024] [Indexed: 04/16/2024] Open
Abstract
Mandible morphology has an essential role in biting performance, but the mandible cuticle can have regional differences in its mechanical properties. The effects of such a heterogeneous distribution of cuticle material properties in the mandible responses to biting loading are still poorly explored in chewing insects. Here, we tested the mechanical properties of mandibles of the ant species Formica cunicularia by nanoindentation and investigated the effects of the cuticular variation in Young's modulus (E) under bite loading with finite-element analysis (FEA). The masticatory margin of the mandible, which interacts with the food, was the hardest and stiffest region. To unravel the origins of the mechanical property gradients, we characterized the elemental composition by energy-dispersive X-ray spectroscopy. The masticatory margin possessed high proportions of Cu and Zn. When incorporated into the FEA, variation in E effectively changed mandible stress patterns, leading to a relatively higher concentration of stresses in the stiffer mandibular regions and leaving the softer mandible blade with relatively lower stress. Our results demonstrated the relevance of cuticle E heterogeneity in mandibles under bite loading, suggesting that the accumulation of transition metals such as Cu and Zn has a relevant correlation with the mechanical characteristics in F. cunicularia mandibles.
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Affiliation(s)
- Cristian L. Klunk
- Animal Evolutionary Ecology, Technische Universität Darmstadt, Schnittspahnstr. 3, Darmstadt 64287, Germany
| | - Michael Heethoff
- Animal Evolutionary Ecology, Technische Universität Darmstadt, Schnittspahnstr. 3, Darmstadt 64287, Germany
| | - Jörg U. Hammel
- Institute of Materials Physics, Helmholtz-Zentrum Hereon, Geesthacht, Germany
| | - Stanislav N. Gorb
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, Kiel 24118, Germany
| | - Wencke Krings
- Department of Functional Morphology and Biomechanics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Am Botanischen Garten 1-9, Kiel 24118, Germany
- Department of Cariology, Endodontology and Periodontology, Universität Leipzig, Liebigstraße 12, Leipzig, Germany
- Department of Electron Microscopy, Institute of Cell and Systems Biology of Animals, Universität Hamburg, Martin-Luther-King-Platz 3, Hamburg 20146, Germany
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Hong H, Kim W, Kim W, Jeong JM, Kim S, Kim SS. Machine Learning-Driven Design Optimization of Buckling-Induced Quasi-Zero Stiffness Metastructures for Low-Frequency Vibration Isolation. ACS Appl Mater Interfaces 2024; 16:17965-17972. [PMID: 38533594 PMCID: PMC11009906 DOI: 10.1021/acsami.3c18793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 03/04/2024] [Accepted: 03/18/2024] [Indexed: 03/28/2024]
Abstract
Metastructures, artificial arrangements of micro/macrostructures, possess unique properties and are of significant interest in aerospace, stealth technology, and various other applications. Recent studies have focused on quasi-zero stiffness metastructures, providing an outstanding vibration isolation capability. However, existing methods are constrained to low preloads and lack the consideration of structural analysis, despite their intended use in practical structures. This study introduces metastructures with quasi-zero stiffness characteristics under high preloads by inducing local buckling. An optimization framework combining deep reinforcement learning and finite-element analysis is employed to derive an optimal model that considers both structural safety and quasi-zero stiffness characteristics. To validate the optimization results, quasi-zero stiffness metastructures are fabricated via 3D printing, and compression and vibration experiments are conducted. The fabricated metastructures exhibit quasi-zero stiffness characteristics under a high target preload along with outstanding vibration reduction performance, even in the low-frequency range.
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Affiliation(s)
- Hyunsoo Hong
- Department of Mechanical
Engineering, Korea Advanced Institute of
Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Wonki Kim
- Department of Mechanical
Engineering, Korea Advanced Institute of
Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Wonvin Kim
- Department of Mechanical
Engineering, Korea Advanced Institute of
Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Jae-moon Jeong
- Department of Mechanical
Engineering, Korea Advanced Institute of
Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Samuel Kim
- Department of Mechanical
Engineering, Korea Advanced Institute of
Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Seong Su Kim
- Department of Mechanical
Engineering, Korea Advanced Institute of
Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
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Cui Y, Liu C, Mu H, Jiang H, Xu F, Liu Y, Hu Q. Analysis of Mechanical Characteristics of the Swing Angle Milling Head of a Heavy Computer Numerical Control Milling Machine and Research on the Light Weight of a Gimbal. Materials (Basel) 2024; 17:324. [PMID: 38255492 DOI: 10.3390/ma17020324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 12/26/2023] [Accepted: 01/02/2024] [Indexed: 01/24/2024]
Abstract
As the key component of a five-axis CNC planer-type milling machine, the integral mechanical property of the A/C swing angle milling head directly affects the machining accuracy and stability of the milling machine. Taking the mechanical A/C swing-angle milling head of a five-axis numerical-control gantry milling machine as the research object, the stress deformation characteristics and natural frequency of the swing-angle milling head under actual working conditions were studied using finite-element analysis. Based on the analytical results, it was determined that the cardan frame, with its large mass proportion and strong rigidity of the whole milling head, is the object to be optimized. The topological optimization of the cardan frame, in which achieving the minimum flexibility was the optimization objective, was carried out to determine the quality reduction area. By comparing the simulation results of the cardan frames of three different rib plate structures, it was shown that the cardan frame performance of the ten-type rib plate structure was optimal. The analytical results showed that, when the cardan frame met the design requirements for stiffness and strength, the mass after optimization was reduced by 13.67% compared with the mass before optimization, the first-order natural frequency was increased by 7.9%, and the maximum response amplitude was reduced in all directions to avoid resonance, which was beneficial to the improvement of the dynamic characteristics of the whole machine. At the same time, the rationality and effectiveness of the lightweight design method of the cardan frame were verified, which has strong engineering practicality. The research results provide an important theoretical basis for the optimization of other machine tool gimbals and have important practical significance and application value.
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Affiliation(s)
- Youzheng Cui
- School of Mechanical and Electronic Engineering, Qiqihar University, Qiqihar 161006, China
- The Engineering Technology Research Center for Precision Manufacturing Equipment and Industrial Perception of Heilongjiang Province, Qiqihar 161006, China
- The Collaborative Innovation Center for Intelligent Manufacturing Equipment Industrialization, Qiqihar 161006, China
| | - Chengxin Liu
- School of Mechanical and Electronic Engineering, Qiqihar University, Qiqihar 161006, China
| | - Haijing Mu
- School of Mechanical and Electronic Engineering, Qiqihar University, Qiqihar 161006, China
| | - Hui Jiang
- Qiqihar Heavy CNC Equipment Co., Ltd., Qiqihar 161005, China
| | - Fengxia Xu
- School of Mechanical and Electronic Engineering, Qiqihar University, Qiqihar 161006, China
- The Engineering Technology Research Center for Precision Manufacturing Equipment and Industrial Perception of Heilongjiang Province, Qiqihar 161006, China
- The Collaborative Innovation Center for Intelligent Manufacturing Equipment Industrialization, Qiqihar 161006, China
| | - Yinfeng Liu
- School of Mechanical and Electronic Engineering, Qiqihar University, Qiqihar 161006, China
- Qiqihar Heavy CNC Equipment Co., Ltd., Qiqihar 161005, China
| | - Qingming Hu
- School of Mechanical and Electronic Engineering, Qiqihar University, Qiqihar 161006, China
- School of Mechatronics Engineering, Harbin Institute of Technology, Harbin 150001, China
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Li T, Chang TS, Shirazi A, Wu X, Lin WK, Zhang R, Guo JL, Oldham KR, Wang TD. Scaling down the dimensions of a Fabry-Perot polymer film acoustic sensor for photoacoustic endoscopy. J Biomed Opt 2024; 29:S11514. [PMID: 38169937 PMCID: PMC10760494 DOI: 10.1117/1.jbo.29.s1.s11514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 11/17/2023] [Accepted: 12/06/2023] [Indexed: 01/05/2024]
Abstract
Significance A Fabry-Perot (FP) polymer film sensor can be used to detect acoustic waves in a photoacoustic endoscope (PAE) if the dimensions can be adequately scaled down in size. Current FP sensors have limitations in size, sensitivity, and array configurability. Aim We aim to characterize and demonstrate the imaging performance of a miniature FP sensor to evaluate the effects of reduced size and finite dimensions. Approach A transfer matrix model was developed to characterize the frequency response of a multilayer miniature FP sensor. An analytical model was derived to describe the effects of a substrate with finite thickness. Finite-element analysis was performed to characterize the temporal response of a sensor with finite dimensions. Miniature 2 × 2 mm 2 FP sensors were designed and fabricated using gold films as reflective mirrors on either side of a parylene C film deposited on a glass wafer. A single-wavelength laser was used to interrogate the sensor using illumination delivered by fiber subprobes. Imaging phantoms were used to verify FP sensor performance, and in vivo images of blood vessels were collected from a live mouse. Results The finite thickness substrate of the FP sensor resulted in echoes in the time domain signal that could be removed by back filtering. The substrate acted as a filter in the frequency domain. The finite lateral sensor dimensions produced side waves that could be eliminated by surface averaging using an interrogation beam with adequate diameter. The fabricated FP sensor produced a noise-equivalent pressure = 0.76 kPa, bandwidth of 16.6 MHz, a spectral full-width at-half-maximum = 0.2886 nm, and quality factor Q = 2694 . Photoacoustic images were collected from phantoms and blood vessels in a live mouse. Conclusions A miniature wafer-based FP sensor design has been demonstrated with scaled down form factor for future use in PAE.
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Affiliation(s)
- Tong Li
- University of Michigan, Department of Mechanical Engineering, Ann Arbor, Michigan, United States
| | - Tse-Shao Chang
- University of Michigan, Department of Mechanical Engineering, Ann Arbor, Michigan, United States
| | - Ahmad Shirazi
- University of Michigan, Division of Integrative Systems and Design, Ann Arbor, Michigan, United States
| | - Xiaoli Wu
- University of Michigan, Department of Internal Medicine, Division of Gastroenterology, Ann Arbor, Michigan, United States
| | - Wei-Kuan Lin
- University of Michigan, Department of Electrical and Computer Engineering, Ann Arbor, Michigan, United States
| | - Ruoliu Zhang
- University of Michigan, Department of Biomedical Engineering, Ann Arbor, Michigan, United States
| | - Jay L. Guo
- University of Michigan, Department of Mechanical Engineering, Ann Arbor, Michigan, United States
- University of Michigan, Department of Electrical and Computer Engineering, Ann Arbor, Michigan, United States
- University of Michigan, Department of Macromolecular Science and Engineering, Ann Arbor, Michigan, United States
- University of Michigan, Department of Applied Physics, Ann Arbor, Michigan, United States
| | - Kenn R. Oldham
- University of Michigan, Department of Mechanical Engineering, Ann Arbor, Michigan, United States
| | - Thomas D. Wang
- University of Michigan, Department of Mechanical Engineering, Ann Arbor, Michigan, United States
- University of Michigan, Department of Internal Medicine, Division of Gastroenterology, Ann Arbor, Michigan, United States
- University of Michigan, Department of Biomedical Engineering, Ann Arbor, Michigan, United States
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Mohan M, Mohammad L, Cholayil N, Vats S, Salman Kuttikkodan M, Kodumbilayiparambil Anto J. Stress Distribution on Maxillary Canines Following Restoration With Different Dimensions of Metal and Fiber Posts: A Finite Element Study. Cureus 2024; 16:e53266. [PMID: 38435932 PMCID: PMC10905048 DOI: 10.7759/cureus.53266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 01/29/2024] [Indexed: 03/05/2024] Open
Abstract
Introduction In recent times, finite element analysis (FEA) in the field of dentistry has been employed to assess the mechanical properties of biological materials and tissues, which are difficult to quantify directly within a living organism. Only a limited number of studies have examined the impact of post diameter and length on how stress is dispersed in a maxillary canine tooth. Hence, this in vitro investigation was conducted to analyze the distribution of stress in a maxillary canine tooth that was replaced using metal and fiber posts with different diameters (1.5 mm and 1.8 mm) and lengths (11 mm and 15 mm), applying FEA. Materials and methods A FEA study was performed and all models were grouped as follows: Models 1 and 5 were made of titanium (Ti) and glass fiber posts, respectively, with a diameter of 1.5 mm and a length of 15 mm with composite core and all-ceramic crown; Models 2 and 6 were made of Ti and glass fiber posts, respectively, with a diameter of 1.5 mm and a length of 11 mm with composite core and all-ceramic crown; Models 3 and 7 were made of Ti and glass fiber posts, respectively, with a diameter of 1.8 mm and a length of 15 mm with composite core and all-ceramic crown; and Models 4 and 8 were made of Ti and glass fiber posts, respectively, with a diameter of 1.8 mm and a length of 11 mm with composite core and all-ceramic crown. A force of 200 N was exerted on the ceramic crown at an angulation of 45° to the longitudinal axis of the tooth on the palatal surface above the cingulum. The failure was determined by the correlation between a larger von Mises stress estimate and an increased likelihood of failure. The resulting stresses were then contrasted with the highest possible tensile strength of the material. Results The study demonstrated that fiber posts with a diameter of 1.8 mm and an average length of 11 mm exhibited reduced stress levels in comparison to Ti posts. The largest stresses were seen at the cervical region of the tooth, regardless of the materials employed. There was no discernible alteration in stress when the length and diameter of the post were modified. The highest stress in the composite core was measured in Ti posts measuring 1.5 mm in diameter and 15 mm in length. The highest level of stress on dentin was noted in cases where a fiber post was used, as opposed to cases where a Ti post was used. The measured stress within the fiber post was insignificant. However, the pressures imparted to the dentin were greater and more uniformly distributed in comparison to the Ti post cases. Conclusion It is suggested that a composite resin core be used along with a fiber post that is larger in diameter and smaller in length, within clinical bounds, in order to lessen stress in the radicular tooth, despite the substantial coronal defect. Further clinical trials are required to assess the survival rate of these specific measurements, dimensions, and biomaterials.
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Affiliation(s)
- Mahesh Mohan
- Department of Conservative Dentistry and Endodontics, Institute of Dental Studies & Technologies, Modinagar, Ghaziabad, IND
| | - Lubna Mohammad
- Department of Endodontics, Danat Al Sahraa Medical Company, Jubail, SAU
| | - Nasarudheen Cholayil
- Department of Conservative Dentistry and Endodontics, Sree Anjaneya Institute of Dental Sciences, Kozhikode, IND
| | - Saumya Vats
- Department of Conservative Dentistry and Endodontics, Institute of Dental Studies & Technologies, Modinagar, Ghaziabad, IND
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Elsamanty M, Elshokrofy H, Ibrahim A, Järvenpää A, Khedr M. Investigation and Tailoring of Rotating Squares' and Rectangles' Auxetic Structure Behavior through Computational Simulations of 6082T6 Aluminum Alloy Structures. Materials (Basel) 2023; 16:7597. [PMID: 38138739 PMCID: PMC10744777 DOI: 10.3390/ma16247597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 12/04/2023] [Accepted: 12/07/2023] [Indexed: 12/24/2023]
Abstract
Auxetic structures, renowned for their unique lateral expansion under longitudinal strain, have attracted significant research interest due to their extraordinary mechanical characteristics, such as enhanced toughness and shear resistance. This study provides a systematic exploration of these structures, constructed from rigid rotating square or rectangular unit cells. Incremental alterations were applied to key geometrical parameters, including the angle (θ) between connected units, the side length (a), the side width (b) of the rotating rigid unit, and the overlap distance (t). This resulted in a broad tunable range of negative Poisson's ratio values from -0.43 to -1.78. Through comprehensive three-dimensional finite-element analyses, the intricate relationships between the geometric variables and the resulting bulk Poisson's ratio of the modeled auxetic structure were elucidated. This analysis affirmed the auxetic behavior of all investigated samples, characterized by lateral expansion under tensile force. The study also revealed potential stress concentration points at interconnections between rotating units, which could impact the material's performance under high load conditions. A detailed investigation of various geometrical parameters yielded fifty unique samples, enabling in-depth observation of the impacts of geometric modifications on the overall behavior of the structures. Notably, an increase in the side width significantly enhanced the Poisson's ratio, while an increase in the overlap distance notably reduced it. The greatest observable change in the Poisson's ratio was a remarkable 202.8%, emphasizing the profound influence of geometric parameter manipulation. A cascaded forward propagation-backpropagation neural network model was deployed to determine the Poisson's ratio for auxetic structures, based on the geometric parameters and material properties of the structure. The model's architecture consisted of five layers with varying numbers of neurons. The model's validity was affirmed by comparing its predictions with FEA simulations, with the maximum error observed in the predicted Poisson's ratio being 8.62%.
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Affiliation(s)
- Mahmoud Elsamanty
- Mechanical Engineering Department, Faculty of Engineering at Shoubra, Benha University, Cairo 11629, Egypt; (H.E.); (A.I.)
- Mechatronics and Robotics Department, School of Innovative Engineering Design, Egypt Japan University of Science and Technology (E-JUST), Alexandria 21934, Egypt
| | - Hassan Elshokrofy
- Mechanical Engineering Department, Faculty of Engineering at Shoubra, Benha University, Cairo 11629, Egypt; (H.E.); (A.I.)
| | - Abdelkader Ibrahim
- Mechanical Engineering Department, Faculty of Engineering at Shoubra, Benha University, Cairo 11629, Egypt; (H.E.); (A.I.)
| | - Antti Järvenpää
- Kerttu Saalasti Institute, Future Manufacturing Technologies (FMT), University of Oulu, 85500 Nivala, Finland;
| | - Mahmoud Khedr
- Mechanical Engineering Department, Faculty of Engineering at Shoubra, Benha University, Cairo 11629, Egypt; (H.E.); (A.I.)
- Kerttu Saalasti Institute, Future Manufacturing Technologies (FMT), University of Oulu, 85500 Nivala, Finland;
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Zhang P, Li J, Zhao Y, Li J. Numerical simulation and experimental verification of fatigue crack propagation in high-strength bolts based on fracture mechanics. Sci Prog 2023; 106:368504231211660. [PMID: 38058131 DOI: 10.1177/00368504231211660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2023]
Abstract
To investigate the fatigue crack propagation behavior of high-strength bolts for high-speed train brake discs, the fatigue crack propagation of high-strength bolts with initial defects under various load ratios was numerically simulated and experimentally verified based on fracture mechanics in this paper. Firstly, the fracture mechanics model of a three-dimensional hexahedral mesh with initial root defects was established using ABAQUS-FRANC3D interactive technology. Then the stress intensity factor (SIF) of the crack front was calculated by the stress superposition of the crack surface to simulate the coupling effect of preload and axial cyclic load. Based on it, fatigue crack propagation was simulated. Finally, the corresponding fatigue experiments on prefabricated crack bolts were carried out. The results show that mode I cracks dominate in the process of crack propagation. The stable crack propagation zones of the fractured high-strength bolts all show a semi-elliptical cross-section. The SIF of the crack front decreases with the increase of the load ratio, thus making the crack propagation life increase with the increase of the load ratio. The experimental outcomes are in great agreement with the simulation results, which verify that the numerical simulation method can effectively and accurately evaluate the fatigue life of high-strength bolts with initial defects and provides an effective means for predicting the fatigue crack propagation life of the same type high-strength bolts in engineering applications.
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Affiliation(s)
- Ping Zhang
- College of Mechanical Engineering, Guizhou University, Guiyang, China
- College of Physics and Electromechanical Engineering, Guizhou Minzu University, Guiyang, China
| | - Jiachun Li
- College of Mechanical Engineering, Guizhou University, Guiyang, China
| | - Yu Zhao
- College of Mechanical Engineering, Guizhou University, Guiyang, China
| | - Jiaxiao Li
- China Aviation Industry Standard Parts Manufacturing Co. LTD, Guiyang, China
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Guo X, Wang Z, Gao L, Zhang C. Parametric optimization of culture chamber for cell mechanobiology research. Exp Biol Med (Maywood) 2023; 248:1708-1717. [PMID: 37837381 PMCID: PMC10792420 DOI: 10.1177/15353702231198079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 06/07/2023] [Indexed: 10/16/2023] Open
Abstract
Mechanical signals influence the morphology, function, differentiation, proliferation, and growth of cells. Due to the small size of cells, it is essential to analyze their mechanobiological responses with an in vitro mechanical loading device. Cells are cultured on an elastic silicone membrane substrate, and mechanical signals are transmitted to the cells by the substrate applying mechanical loads. However, large areas of non-uniform strain fields are generated on the elastic membrane, affecting the experiment's accuracy. In the study, finite-element analysis served as the basis of optimization, with uniform strain as the objective. The thickness of the basement membrane and loading constraints were parametrically adjusted. Through finite-element cycle iteration, the "M" profile basement membrane structure of the culture chamber was obtained to enhance the uniform strain field of the membrane. The optimized strain field of culture chamber was confirmed by three-dimensional digital image correlation (3D-DIC) technology. The results showed that the optimized chamber improved the strain uniformity factor. The uniform strain area proportion of the new chamber reached 90%, compared to approximately 70% of the current chambers. The new chamber further improved the uniformity and accuracy of the strain, demonstrating promising application prospects.
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Affiliation(s)
- Xutong Guo
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin 300384, China
- National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin 300384, China
| | - Ziqi Wang
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin 300384, China
- National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin 300384, China
| | - Lilan Gao
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin 300384, China
- National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin 300384, China
| | - Chunqiu Zhang
- Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control, School of Mechanical Engineering, Tianjin University of Technology, Tianjin 300384, China
- National Demonstration Center for Experimental Mechanical and Electrical Engineering Education, Tianjin University of Technology, Tianjin 300384, China
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Bekele A, Wadee MA, Phillips ATM. Enhancing energy absorption through sequential instabilities in mechanical metamaterials. R Soc Open Sci 2023; 10:230762. [PMID: 37650064 PMCID: PMC10465199 DOI: 10.1098/rsos.230762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 08/07/2023] [Indexed: 09/01/2023]
Abstract
Structural components designed to absorb energy and shield a more valuable structure ideally require mechanical properties that combine a relatively high load-carrying capacity followed by a practically zero stiffness. This ensures that a specified energy quantity may be absorbed within a limited displacement and that any stress transfer to the valuable structure is minimized. Material damage has been historically mobilized to provide such properties, but this obviously renders such components to be single-use. By contrast, mobilization of elastic instability can also provide the desired combination of properties but without necessarily damaging the material. This reveals an intriguing possibility of such components being potentially repairable and theoretically re-usable with no significant loss in performance. A series of analytical, finite-element and experimental studies are presented for a bespoke mechanical metamaterial arrangement that is designed to buckle sequentially and behave with the desired 'high strength-low stiffness' characteristic. It is found that the various axial and rotational stiffnesses associated with the geometric arrangement and its constituent connections may be tuned to provide the desired mechanical behaviour within the elastic range and delay the onset of significant damage, thereby rendering the concept of harnessing instability to be feasible.
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Affiliation(s)
- Adam Bekele
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK
| | - M. Ahmer Wadee
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK
| | - Andrew T. M. Phillips
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK
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Crascì F, Cannata S, Gentile G, Gandolfo C, Pasta S. Biomechanical performance of the Bicaval Transcatheter System for the treatment of severe tricuspid regurgitation. Front Bioeng Biotechnol 2023; 11:1179774. [PMID: 37274165 PMCID: PMC10234501 DOI: 10.3389/fbioe.2023.1179774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Accepted: 05/09/2023] [Indexed: 06/06/2023] Open
Abstract
Introduction: Tricuspid regurgitation (TR) is a relatively common valvular disease, which can result from structural abnormalities of any anatomic part of the tricuspid valve. Severe TR is linked to congestive heart failure and hemodynamic impairment, resulting in high mortality when repaired by elective surgery. This study was undertaken to quantify the structural and hemodynamic performance of the novel Transcatheter Bicaval Valves System (TricValve) percutaneously implanted in the superior vena cava (SVC) and inferior vena cava (IVC) of two patients with severe TR and venous congestion. Methods: After developing the SVC and IVC device models, the contact pressure exerted on the vena cava wall was obtained by computational analysis. Both smoothed-particle hydrodynamics (SPH) and computational fluid dynamics were carried out to quantify caval reflux in the right atrium and the pressure field of pre- and post-TricValve scenarios, respectively. Results: Analysis of contact pressure highlighted the main anchoring area of the SVC device occurring near the SVC device belly, while the IVC device exerted pronounced forces in the device's proximal and distal parts. SPH-related flow velocities revealed the absence of caval reflux, and a decrease in time-averaged pressure was observed near the SVC and IVC after TricValve implantation. Discussion: Findings demonstrated the potential of computational tools for enhancing our understanding of the biomechanical performance of structural tricuspid valve interventions and improving the way we design next-generation transcatheter therapies to treat the tricuspid valve with heterotopic caval valve implantation.
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Affiliation(s)
- Fabrizio Crascì
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
- Department of Research, IRCCS-ISMETT, Palermo, Italy
| | - Stefano Cannata
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Palermo, Italy
| | - Giovanni Gentile
- Radiology Unit, Department of Diagnostic and Therapeutic Services, IRCCS-ISMETT, Palermo, Italy
| | - Caterina Gandolfo
- Department for the Treatment and Study of Cardiothoracic Diseases and Cardiothoracic Transplantation, IRCCS-ISMETT, Palermo, Italy
| | - Salvatore Pasta
- Department of Engineering, Università degli Studi di Palermo, Palermo, Italy
- Department of Research, IRCCS-ISMETT, Palermo, Italy
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11
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Chhaya V, Reddy S, Krishnan A. Bill shape imposes biomechanical tradeoffs in cavity-excavating birds. Proc Biol Sci 2023; 290:20222395. [PMID: 36987643 PMCID: PMC10050923 DOI: 10.1098/rspb.2022.2395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
Abstract
Organisms are subject to physical forces that influence morphological evolution. Birds use their bills as implements to perform various functions, each exerting unique physical demands. When excavating cavities, bird bills must resist a range of mechanical stresses to prevent fracture. However, the contribution of bill geometry and material composition to excavation stress resistance remains poorly understood. Here, we study the biomechanical consequences of bill diversification in the cavity-excavating palaeotropical barbets. Using finite-element models and beam theory, we compare excavation performance for two loading regimes experienced by barbet bills during cavity excavation: impact and torsion. We find that deeper and wider maxillae perform better for impact loads than for torsional loads, with the converse for narrower maxillae. This results in tradeoffs between impact and torsion resistance imposed by bill geometry. Analytical beam models validate this prediction, showing that this relationship holds even when maxillae are simplified to solid elliptical beams. Finally, we find that composite bill structures broadly exhibit lower stresses than homogeneous structures of the same geometry, indicating a functional synergy between the keratinous rhamphotheca and bony layers of the bill. Overall, our findings demonstrate the strong link between morphological evolution, behaviour and functional performance in organisms.
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Affiliation(s)
- Vaibhav Chhaya
- Department of Biology, Indian Institute of Science Education and Research (IISER) Pune, Pashan Road, Pune 411008, India
| | - Sushma Reddy
- Bell Museum of Natural History and Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, St. Paul, MN 55108, USA
| | - Anand Krishnan
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Bhauri, Madhya Pradesh 462066, India
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12
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Gupta P, Ruzicka E, Benicewicz BC, Sundararaman R, Schadler LS. Dielectric Properties of Polymer Nanocomposite Interphases Using Electrostatic Force Microscopy and Machine Learning. ACS Appl Electron Mater 2023; 5:794-802. [PMID: 36873258 PMCID: PMC9979787 DOI: 10.1021/acsaelm.2c01331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/27/2022] [Indexed: 06/18/2023]
Abstract
Knowing the dielectric properties of the interfacial region in polymer nanocomposites is critical to predicting and controlling dielectric properties. They are, however, difficult to characterize due to their nanoscale dimensions. Electrostatic force microscopy (EFM) provides a pathway to local dielectric property measurements, but extracting local dielectric permittivity in complex interphase geometries from EFM measurements remains a challenge. This paper demonstrates a combined EFM and machine learning (ML) approach to measuring interfacial permittivity in 50 nm silica particles in a PMMA matrix. We show that ML models trained to finite-element simulations of the electric field profile between the EFM tip and nanocomposite surface can accurately determine the interface permittivity of functionalized nanoparticles. It was found that for the particles with a polyaniline brush layer, the interfacial region was detectable (extrinsic interface). For bare silica particles, the intrinsic interface was detectable only in terms of having a slightly higher or lower permittivity. This approach fully accounts for the complex interplay of filler, matrix, and interface permittivity on the force gradients measured in EFM that are missed by previous semianalytic approaches, providing a pathway to quantify and design nanoscale interface dielectric properties in nanodielectric materials.
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Affiliation(s)
- Praveen Gupta
- College
of Engineering and Mathematical Sciences, University of Vermont, Burlington, Vermont05405, United States
- Department
of Materials Science and Engineering, Rensselaer
Polytechnic Institute, Troy, New York12180, United States
| | - Eric Ruzicka
- College
of Arts and Sciences, University of South
Carolina, Columbia, South Carolina29208, United States
| | - Brian C. Benicewicz
- College
of Arts and Sciences, University of South
Carolina, Columbia, South Carolina29208, United States
| | - Ravishankar Sundararaman
- Department
of Materials Science and Engineering, Rensselaer
Polytechnic Institute, Troy, New York12180, United States
| | - Linda S. Schadler
- College
of Engineering and Mathematical Sciences, University of Vermont, Burlington, Vermont05405, United States
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13
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Gong T, Luo Y, Lu M, Wang J, Zhang Y, Wang Y, Tang F, Li Z, Zhou Y, Min L, Tu C. The optimal strategy for 3D-printed uncemented endoprosthesis for the bone defect reconstruction of the distal radius, based on biomechanical analysis and retrospective cohort study. J Surg Oncol 2023; 127:1043-1053. [PMID: 36825890 DOI: 10.1002/jso.27215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/01/2023] [Accepted: 02/06/2023] [Indexed: 02/25/2023]
Abstract
INTRODUCTION Prosthetic reconstruction after resecting giant cell tumor of bone (GCTB) of the distal radius has been proposed. However, this is generally associated with various complications. To improve the functional outcomes, we designed a three-dimensional (3D)-printed uncemented endoprosthesis. Meanwhile, using finite-element analysis and clinical observation, an optimization strategy was explored. MATERIALS AND METHODS We retrospectively analyzed patients with Campanacci III or recurrent GCTB of the distal radius who underwent 3D-printed uncemented endoprosthesis reconstruction. Clinically, according to the different palmar tilts of the endoprosthesis, patients were divided into the biological angle (BA) group and the zero-degree (ZD) group. We recorded and evaluated the differences in functional outcomes and complications between the two groups. Biomechanically, four 3D finite-element models (normal and customized endoprostheses with three different implemented palmar tilts) were developed. RESULTS We analyzed 22 patients (12 males and 10 females). The median follow-up period was 60 (range, 19-82) months. Of the 22 patients, 11 patients were included in the BA group and the remaining 11 patients were in the ZD group. Both groups showed no significant differences in the range of motion, Mayo score, and disabilities of the arm, shoulder, and hand scores postoperatively. The subluxation rate was significantly lower in the ZD group than in the BA group. The biomechanical results showed similar stress and displacement distribution patterns in the normal and prosthetic reconstruction models. Additionally, the endoprosthesis with 0° palmar tilt showed better biomechanical performance. CONCLUSION 3D-printed uncemented endoprosthesis provides acceptable midterm outcomes in patients undergoing distal radius reconstruction. Optimizing the design by decreasing the palmar tilt may be beneficial for decreasing the risk of wrist joint subluxation.
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Affiliation(s)
- Taojun Gong
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Yi Luo
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Minxun Lu
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Jie Wang
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Yuqi Zhang
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Yitian Wang
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Fan Tang
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Zhuangzhuang Li
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Yong Zhou
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Li Min
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
| | - Chongqi Tu
- Department of Orthopedics, West China Hospital, Orthopaedic Research Institute , Sichuan University, Chengdu, People's Republic of China.,Model Worker and Craftsman Talent Innovation Workshop of Sichuan Province, Chengdu, Sichuan, People's Republic of China
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14
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Button DJ, Porro LB, Lautenschlager S, Jones MEH, Barrett PM. Multiple pathways to herbivory underpinned deep divergences in ornithischian evolution. Curr Biol 2023; 33:557-565.e7. [PMID: 36603586 DOI: 10.1016/j.cub.2022.12.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/28/2022] [Accepted: 12/08/2022] [Indexed: 01/06/2023]
Abstract
The extent to which evolution is deterministic is a key question in biology,1,2,3,4,5,6,7,8,9 with intensive debate on how adaptation6,10,11,12,13 and constraints14,15,16 might canalize solutions to ecological challenges.4,5,6 Alternatively, unique adaptations1,9,17 and phylogenetic contingency1,3,18 may render evolution fundamentally unpredictable.3 Information from the fossil record is critical to this debate,1,2,11 but performance data for extinct taxa are limited.7 This knowledge gap is significant, as general morphology may be a poor predictor of biomechanical performance.17,19,20 High-fiber herbivory originated multiple times within ornithischian dinosaurs,21 making them an ideal clade for investigating evolutionary responses to similar ecological pressures.22 However, previous biomechanical modeling studies on ornithischian crania17,23,24,25 have not compared early-diverging taxa spanning independent acquisitions of herbivory. Here, we perform finite-element analysis on the skull of five early-diverging members of the major ornithischian clades to characterize morphofunctional pathways to herbivory. Results reveal limited functional convergence among ornithischian clades, with each instead achieving comparable performance, in terms of reconstructed patterns and magnitudes of functionally induced stress, through different adaptations of the feeding apparatus. Thyreophorans compensated for plesiomorphic low performance through increased absolute size, heterodontosaurids expanded jaw adductor muscle volume, ornithopods increased jaw system efficiency, and ceratopsians combined these approaches. These distinct solutions to the challenges of herbivory within Ornithischia underpinned the success of this diverse clade. Furthermore, the resolution of multiple solutions to equivalent problems within a single clade through macroevolutionary time demonstrates that phenotypic evolution is not necessarily predictable, instead arising from the interplay of adaptation, innovation, contingency, and constraints.1,2,3,7,8,9,18.
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Affiliation(s)
- David J Button
- Science Group, The Natural History Museum, Cromwell Road, London SW7 5BD, UK.
| | - Laura B Porro
- Centre for Integrative Anatomy, Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6DE, UK
| | - Stephan Lautenschlager
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Marc E H Jones
- Science Group, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Paul M Barrett
- Science Group, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
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15
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Chatar N, Fischer V, Tseng ZJ. Many-to-one function of cat-like mandibles highlights a continuum of sabre-tooth adaptations. Proc Biol Sci 2022; 289:20221627. [PMID: 36475442 PMCID: PMC9727663 DOI: 10.1098/rspb.2022.1627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cat-like carnivorans are a textbook example of convergent evolution, with distinct morphological differences between taxa with short or elongated upper canines, the latter often being interpreted as an adaptation to bite at large angles and subdue large prey. This interpretation of the sabre-tooth condition is reinforced by a reduced taxonomic sampling in some studies, often focusing on highly derived taxa or using simplified morphological models. Moreover, most biomechanical analyses focus on biting scenarios at small gapes, ideal for modern carnivora but ill-suited to test for subduction of large prey by sabre-toothed taxa. In this contribution, we present the largest three-dimensional collection-based muscle-induced biting simulations on cat-like carnivorans by running a total of 1074 analyses on 17 different taxa at three different biting angles (30°, 60° and 90°) including both morphologies. While our results show a clear adaptation of extreme sabre-toothed taxa to bite at larger angles in terms of stress distribution, other performance variables display surprising similarities between all forms at the different angles tested, highlighting a continuous rather than bipolar spectrum of hunting methods in cat-like carnivorans and demonstrating a wide functional disparity and nuances of the sabre-tooth condition that cannot simply be characterized by specialized feeding biomechanics.
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Affiliation(s)
- Narimane Chatar
- Evolution and Diversity Dynamics lab, UR Geology, Université de Liège, Building B18, Quartier Agora, Allée du Six Août 14, Liège, 4000, Belgium
| | - Valentin Fischer
- Evolution and Diversity Dynamics lab, UR Geology, Université de Liège, Building B18, Quartier Agora, Allée du Six Août 14, Liège, 4000, Belgium
| | - Z. Jack Tseng
- Department of Integrative Biology and Museum of Paleontology, University of California, Berkeley, CA 94720, USA
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16
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Bennion NJ, Zappalá S, Potts M, Woolley M, Marshall D, Evans SL. In vivo measurement of human brain material properties under quasi-static loading. J R Soc Interface 2022; 19:20220557. [PMID: 36514891 PMCID: PMC9748497 DOI: 10.1098/rsif.2022.0557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Computational modelling of the brain requires accurate representation of the tissues concerned. Mechanical testing has numerous challenges, in particular for low strain rates, like neurosurgery, where redistribution of fluid is biomechanically important. A finite-element (FE) model was generated in FEBio, incorporating a spring element/fluid-structure interaction representation of the pia-arachnoid complex (PAC). The model was loaded to represent gravity in prone and supine positions. Material parameter identification and sensitivity analysis were performed using statistical software, comparing the FE results to human in vivo measurements. Results for the brain Ogden parameters µ, α and k yielded values of 670 Pa, -19 and 148 kPa, supporting values reported in the literature. Values of the order of 1.2 MPa and 7.7 kPa were obtained for stiffness of the pia mater and out-of-plane tensile stiffness of the PAC, respectively. Positional brain shift was found to be non-rigid and largely driven by redistribution of fluid within the tissue. To the best of our knowledge, this is the first study using in vivo human data and gravitational loading in order to estimate the material properties of intracranial tissues. This model could now be applied to reduce the impact of positional brain shift in stereotactic neurosurgery.
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Affiliation(s)
| | - Stefano Zappalá
- School of Computer Science and Informatics, Cardiff University, Cardiff CF24 3AA, UK,Cardiff University Brain Research Imaging Centre (CUBRIC), School of Psychology, Cardiff University, Cardiff CF24 4HQ, UK
| | - Matthew Potts
- School of Engineering, Cardiff University, Cardiff CF10 3AT, UK
| | - Max Woolley
- Functional Neurosurgery Research Group, School of Clinical Sciences, University of Bristol, Bristol, UK,Renishaw Neuro Solutions Ltd, Wotton Road, Wotton-under-Edge GL12 8SP, UK
| | - David Marshall
- School of Computer Science and Informatics, Cardiff University, Cardiff CF24 3AA, UK
| | - Sam L. Evans
- School of Engineering, Cardiff University, Cardiff CF10 3AT, UK
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17
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Li T, Díaz-Real JA, Holm T. Design of Electrochemical Microfluidic Detectors: Accurate Potential Measurement. ACS Sens 2022; 7:2934-2939. [PMID: 36129391 DOI: 10.1021/acssensors.2c00785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Potential drop due to the electrolyte conductivity between the reference electrode (RE) and the working electrode leads to measurement error. Because of the limited amount of electrolyte and constricted geometry in microfluidic systems, the total potential drop in a microfluidic system is confined within a small part of the cell. This makes the choice and placement of the RE an important consideration. In this article, we discuss ways to incorporate an RE in a microfluidic system and, through numerical modeling and experimental verification, present some design strategies for electrode placement to ensure accurate potential control.
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Affiliation(s)
- Tianyu Li
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Rd, Toronto, Ontario M5S 3G8, Canada
| | - Jesús Adrián Díaz-Real
- Centro de Investigación y Desarrollo Tecnológico en Electroquímica, S.C. Parque Tecnológico Querétaro, S/N, Sanfandila, C.P. 76703, Pedro Escobedo, Querétaro, México
| | - Thomas Holm
- Institute for Energy Technology, P.O. Box 40, Kjeller NO-2027, Norway
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18
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Weng R, Huang XC, Ye LQ, Yang CK, Cai ZY, Xu YR, Cui JC, Yi SH, Liang D, Yao ZS. Investigating the mechanical effect of the sagittal angle of the cervical facet joint on the cervical intervertebral disc. Digit Health 2022; 8:20552076221134456. [PMID: 36312849 PMCID: PMC9608055 DOI: 10.1177/20552076221134456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 10/05/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Facet tropism is defined as the asymmetry between the left and right facet joints relative to the sagittal plane. Published clinical studies have found that facet tropism is associated with cervical disc herniation. However, the relationship between the facet orientation and the side of cervical disc herniation remains controversial. Therefore, this study used the finite-element technique to investigate the biomechanical effects of the sagittal angle of the cervical facet joints on the cervical intervertebral disc. OBJECTIVE The biomechanical effects of the sagittal angle of the cervical facet joint on the cervical disc and facet joint were investigated using the finite-element technique. METHODS The finite-element model was constructed using computed tomography scans of a 26-year-old female volunteer. First, a cervical model was constructed from C3 to C7. The model was verified using data from previously published studies. Second, the facet orientation at the C5-C6 level was altered to simulate different sagittal angles of cervical facet joints. Five models, F70, F80, F90, F100, and F110, were simulated with different facet joint orientations (70°, 80°, 90°, 100°, and 110° facet joint angles at the left side, respectively, and 90° facet joint angles at the right side) at the C5-C6 facet joints. In each model, annular fibres stress and facet cartilage pressure were studied under six pure moments and two combined moments. RESULTS Comparing the stress of the annulus fibres in flexion combined with right axial rotation and in flexion combined with left axial rotation in the same model, no difference in the maximum stress of the annulus fibres was noted between these two different moments in the F90 model, whereas differences of 12.80%, 8.84%, 14.95% and 33.32% were noted in the F70, F80, F100 and F110 models, respectively. The same trend was observed when comparing the maximum stress of the annulus fibres in each model during left and right axial rotation. No differences in annular fibres stress and facet cartilage pressure were noted among the five models in flexion, extension, lateral bending, left axial rotation, and flexion combined with left axial rotation in this study. However, compared with the F70 model in flexion combined with right axial rotation, the annulus fibres stress of the F80, F90, F100, and F110 models increased by 5.53%, 13.03%, 35.04%, and 72.94%, respectively, and the pressure of the left facet joint of these models decreased by 5.65%, 12.10%, 18.41%, and 25.74%, respectively. The same trend was observed in the right axial moment. CONCLUSION Facet tropism leads to unbalanced stress distribution on the annulus fibres at the cervical intervertebral disc. The greater the sagittal angle of the facet joint, the greater the annular fibres stress on this side. We hypothesised that the side with the larger sagittal angle of the facet joint exhibits a greater risk of disc herniation.
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Affiliation(s)
- Rui Weng
- Department of Spinal Surgery, The Third Affiliated Hospital of Guangzhou University of Chinese Medicine, China,Guangdong Research Institute for Orthopedics & Traumatology of Chinese Medicine, China
| | - Xue-Cheng Huang
- Department of Spinal Surgery, Shenzhen Hospital of Guangzhou University of Chinese Medicine (Futian), China
| | - Lin-Qiang Ye
- Department of Spinal Surgery, Dongguan Hospital of Traditional Chinese Medicine, China,Lin-Qiang Ye, Dongguan Hospital of Traditional Chinese Medicine, 22 Songshan Lake Avenue, Dongcheng District, Dongguan, 523000, China.
| | - Ce-Kai Yang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, China
| | - Zhuo-Yan Cai
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, China
| | - Yue-Rong Xu
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, China
| | - Jian-Chao Cui
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, China
| | - Sheng-Hui Yi
- Department of Spinal Surgery, Yueyang Hospital of Traditional Chinese Medicine, China
| | - De Liang
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, China
| | - Zhen-Song Yao
- Department of Spinal Surgery, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, China,Baiyun Hospital of the First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong, China,Zhen-Song Yao, Baiyun Hospital of the First Affiliated Hospital of Guangzhou University of Chinese Medicine, Helong 7 Road, Baiyun District, Guangzhou, 510000, China.
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19
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Celiker E, Woodrow C, Rocha-Sánchez AY, Chivers BD, Barrientos-Lozano L, Montealegre-Z F. Beyond the exponential horn: a bush-cricket with ear canals which function as coupled resonators. R Soc Open Sci 2022; 9:220532. [PMID: 36312569 PMCID: PMC9554516 DOI: 10.1098/rsos.220532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 09/14/2022] [Indexed: 06/16/2023]
Abstract
Bush-crickets have dual-input, tympanal ears located in the tibia of their forelegs. The sound will first of all reach the external sides of the tympana, before arriving at the internal sides through the bush-cricket's ear canal, the acoustic trachea (AT), with a phase lapse and pressure gain. It has been shown that for many bush-crickets, the AT has an exponential horn-shaped morphology and function, producing a significant pressure gain above a certain cut-off frequency. However, the underlying mechanism of different AT designs remains elusive. In this study, we demonstrate that the AT of the duetting Phaneropterinae bush-cricket Pterodichopetala cieloi function as coupled resonators, producing sound pressure gains at the sex-specific conspecific calling song frequency, and attenuating the remainder-a functioning mechanism significantly different from an exponential horn. Furthermore, it is demonstrated that despite the sexual dimorphism between the P. cieloi AT, both male and female AT have a similar biophysical mechanism. The analysis was carried out using an interdisciplinary approach, where micro-computed tomography was used for the morphological properties of the P. cieloi AT, and a finite-element analysis was applied on the precise tracheal geometry to further justify the experimental results and to go beyond experimental limitations.
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Affiliation(s)
- Emine Celiker
- University of Lincoln, School of Life and Environmental Sciences, Joseph Banks Laboratories, Green Lane, Lincoln LN6 7DL, UK
| | - Charlie Woodrow
- University of Lincoln, School of Life and Environmental Sciences, Joseph Banks Laboratories, Green Lane, Lincoln LN6 7DL, UK
| | - Aurora Y. Rocha-Sánchez
- Tecnológico Nacional de México-I. T. de Ciudad Victoria, Blvd. Emilio Portes Gil No. 1301, Ciudad Victoria, C.P. 87010 Tamaulipas, México
| | - Benedict D. Chivers
- University of Lincoln, School of Life and Environmental Sciences, Joseph Banks Laboratories, Green Lane, Lincoln LN6 7DL, UK
| | - Ludivina Barrientos-Lozano
- Tecnológico Nacional de México-I. T. de Ciudad Victoria, Blvd. Emilio Portes Gil No. 1301, Ciudad Victoria, C.P. 87010 Tamaulipas, México
| | - Fernando Montealegre-Z
- University of Lincoln, School of Life and Environmental Sciences, Joseph Banks Laboratories, Green Lane, Lincoln LN6 7DL, UK
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20
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Kitamura K, Fujii M, Ikemura S, Hamai S, Motomura G, Nakashima Y. Factors Associated With Abnormal Joint Contact Pressure After Periacetabular Osteotomy: A Finite-Element Analysis. J Arthroplasty 2022; 37:2097-2105.e1. [PMID: 35526756 DOI: 10.1016/j.arth.2022.04.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 04/16/2022] [Accepted: 04/29/2022] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Identifying factors associated with poor hip contact mechanics after periacetabular osteotomy (PAO) may help surgeons optimize acetabular corrections in individual patients. We performed individual-specific finite-element analyses to identify preoperative morphological and surgical correction factors for abnormal contact pressure (CP) after PAO. METHODS We performed finite-element analyses before and after PAO with reference to the standing pelvic position on individual-specific 3-dimensional hip models created from computed tomography images of 51 dysplastic hips. Nonlinear contact analyses were performed to calculate the joint CP of the acetabular cartilage during a single-leg stance. RESULTS The maximum CP decreased in 50 hips (98.0%) after PAO compared to preoperative values, and the resulting maximum CP was within the normal range (<4.1 MPa) in 33 hips (64.7%). Multivariate analysis identified the roundness index of the femoral head (P = .002), postoperative anterior center-edge angle (CEA; P = .004), and surgical correction of lateral CEA (Δlateral CEA; P = .003) as independent predictors for abnormal CP after PAO. A preoperative roundness index >54.3°, a postoperative anterior CEA <36.3°, and a Δlateral CEA >27.0° in the standing pelvic position predicted abnormal CP after PAO. CONCLUSION PAO normalized joint CP in 64.7% of the patients but was less likely to normalize joint CP in patients with aspheric femoral heads. Successful surgical treatment depends on obtaining adequate anterior coverage and avoiding excessive lateral correction, while considering the physiological pelvic tilt in a weight-bearing position.
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Affiliation(s)
- Kenji Kitamura
- Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Masanori Fujii
- Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Department of Orthopaedic Surgery, Faculty of Medicine, Saga University, Saga, Japan
| | - Satoshi Ikemura
- Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Satoshi Hamai
- Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Goro Motomura
- Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yasuharu Nakashima
- Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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21
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Wang S, Zhang D, Li M, Gao L, Chen M, Yang F, Sheng W. Highly efficient thermal deformation optimization method for smart-cut mirrors over the entire photon energy range. J Synchrotron Radiat 2022; 29:1152-1156. [PMID: 36073873 PMCID: PMC9455215 DOI: 10.1107/s1600577522007160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 07/12/2022] [Indexed: 06/15/2023]
Abstract
A method to optimize the notches of water-cooled white-beam mirrors over the entire photon energy range is proposed. A theoretical method is used to quantitatively evaluate the influence of the thermal load on the thermal deformation of a mirror. The result of theoretical calculations and finite-element analysis are consistent, which proves the feasibility of the method. The root mean square of the curvatures of the thermal deformation of the white-beam mirror over the entire photon energy range can be minimized. This method greatly simplifies the design work of water-cooled white-beam mirrors.
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Affiliation(s)
- Shaofeng Wang
- Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, People’s Republic of China
| | - Dongni Zhang
- Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Ming Li
- Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
| | - Lidan Gao
- Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, People’s Republic of China
| | - Minwei Chen
- Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, People’s Republic of China
| | - Fugui Yang
- Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, People’s Republic of China
| | - Weifan Sheng
- Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, People’s Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China
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22
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Dinges GF, Bockemühl T, Iacoviello F, Shearing PR, Büschges A, Blanke A. Ultra high-resolution biomechanics suggest that substructures within insect mechanosensors decisively affect their sensitivity. J R Soc Interface 2022; 19:20220102. [PMID: 35506211 PMCID: PMC9065962 DOI: 10.1098/rsif.2022.0102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Insect load sensors, called campaniform sensilla (CS), measure strain changes within the cuticle of appendages. This mechanotransduction provides the neuromuscular system with feedback for posture and locomotion. Owing to their diverse morphology and arrangement, CS can encode different strain directions. We used nano-computed tomography and finite-element analysis to investigate how different CS morphologies within one location—the femoral CS field of the leg in the fruit fly Drosophila—interact under load. By investigating the influence of CS substructures' material properties during simulated limb displacement with naturalistic forces, we could show that CS substructures (i.e. socket and collar) influence strain distribution throughout the whole CS field. Altered socket and collar elastic moduli resulted in 5% relative differences in displacement, and the artificial removal of all sockets caused differences greater than 20% in cap displacement. Apparently, CS sockets support the distribution of distal strain to more proximal CS, while collars alter CS displacement more locally. Harder sockets can increase or decrease CS displacement depending on sensor location. Furthermore, high-resolution imaging revealed that sockets are interconnected in subcuticular rows. In summary, the sensitivity of individual CS is dependent on the configuration of other CS and their substructures.
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Affiliation(s)
- Gesa F Dinges
- Institute of Zoology, University of Cologne, 50674 Cologne, Germany
| | - Till Bockemühl
- Institute of Zoology, University of Cologne, 50674 Cologne, Germany
| | - Francesco Iacoviello
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, WC1DE 6BT London, UK
| | - Paul R Shearing
- Electrochemical Innovation Lab, Department of Chemical Engineering, University College London, WC1DE 6BT London, UK
| | - Ansgar Büschges
- Institute of Zoology, University of Cologne, 50674 Cologne, Germany
| | - Alexander Blanke
- Institute of Zoology, University of Cologne, 50674 Cologne, Germany.,Institute of Evolutionary Biology and Ecology, University of Bonn, 53121 Bonn, Germany
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23
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Bainbridge EV, Griffiths JD, Clunan J, Docker P. Effect of clamping force on distortion of the optical surface of monochromators during assembly. J Synchrotron Radiat 2022; 29:871-875. [PMID: 35511020 PMCID: PMC9070701 DOI: 10.1107/s1600577522003149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 03/23/2022] [Indexed: 06/14/2023]
Abstract
As Diamond Light Source embraces the move towards becoming a fourth-generation light source its optics will be required to perform under increasingly demanding conditions. Foremost amongst these conditions will be the increasing power densities the optics are subjected to and the reducing real estate they have to perform in. With these new challenges comes the need for greater understanding of how optics are assembled and how consistently the activity is carried out. In this paper, the effect of bolt pretension during assembly of monochromators on distortion of the optical surface is investigated through numerical simulation. The results reveal skewed convex distortion of the optical surface in the meridional direction when uneven clamping force is applied, highlighting the importance of taking the potential for distortion of the optical surface due to clamping force into consideration.
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Affiliation(s)
| | - Jonathan David Griffiths
- School of Engineering, University of Lincoln, Brayford Way, Brayford Pool, Lincoln LN6 7TS, United Kingdom
| | - Jessica Clunan
- School of Engineering, University of Lincoln, Brayford Way, Brayford Pool, Lincoln LN6 7TS, United Kingdom
| | - Peter Docker
- Diamond Light Source, Diamond House, Harwell Science and Innovation Campus, Fermi Avenue, Didcot OX11 0DE, United Kingdom
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24
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van Heteren AH, Wroe S, Tsang LR, Mitchell DR, Ross P, Ledogar JA, Attard MRG, Sustaita D, Clausen P, Scofield RP, Sansalone G. New Zealand's extinct giant raptor ( Hieraaetus moorei) killed like an eagle, ate like a condor. Proc Biol Sci 2021; 288:20211913. [PMID: 34847767 PMCID: PMC8634616 DOI: 10.1098/rspb.2021.1913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 11/10/2021] [Indexed: 01/21/2023] Open
Abstract
The extinct Haast's eagle or harpagornis (Hieraaetus moorei) is the largest known eagle. Historically, it was first considered a predator, then a scavenger, but most recent authors have favoured an active hunting ecology. However, the veracity of proposed similarities to carrion feeders has not been thoroughly tested. To infer feeding capability and behaviour in harpagornis, we used geometric morphometric and finite-element analyses to assess the shape and biomechanical strength of its neurocranium, beak and talons in comparison to five extant scavenging and predatory birds. The neurocranium of harpagornis is vulture-like in shape whereas its beak is eagle-like. The mechanical performance of harpagornis is closer to extant eagles under biting loads but is closest to the Andean condor (Vultur gryphus) under extrinsic loads simulating prey capture and killing. The talons, however, are eagle-like and even for a bird of its size, able to withstand extremely high loads. Results are consistent with the proposition that, unlike living eagles, harpagornis habitually killed prey larger than itself, then applied feeding methods typical of vultures to feed on the large carcasses. Decoupling of the relationship between neurocranium and beak shape may have been linked to rapid evolution.
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Affiliation(s)
- A. H. van Heteren
- Sektion Mammalogie, Zoologische Staatssammlung München - Staatliche Naturwissenschaftliche Sammlungen Bayerns, Münchhausenstraße 21, 81247 Munich, Germany
- GeoBio-Center, Ludwig-Maximilians-Universität München, Richard-Wagner-Straße 10, 80333 Munich, Germany
- Department Biologie II, Ludwig-Maximilians-Universität München, Großhaderner Straße 2, 82152 Planegg-Martinsried, Germany
- School of Environmental and Rural Science, University of New England, Earth Sciences Building, NSW 2351 Armidale, Australia
| | - S. Wroe
- School of Environmental and Rural Science, University of New England, Earth Sciences Building, NSW 2351 Armidale, Australia
| | - L. R. Tsang
- School of Environmental and Rural Science, University of New England, Earth Sciences Building, NSW 2351 Armidale, Australia
- Ornithology Collection, Australian Museum Research Institute, 1 William Street, Sydney, Australia
| | - D. R. Mitchell
- School of Environmental and Rural Science, University of New England, Earth Sciences Building, NSW 2351 Armidale, Australia
- College of Science and Engineering, Flinders University, SA 5042 Adelaide, Australia
| | - P. Ross
- School of Engineering, University of Newcastle, NSW 2308 Newcastle, Australia
| | - J. A. Ledogar
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27798, USA
| | - M. R. G. Attard
- School of Environmental and Rural Science, University of New England, Earth Sciences Building, NSW 2351 Armidale, Australia
- School of Engineering and Innovation, Open University: Milton Keynes, Buckinghamshire, UK
- Department of Biological Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, UK
| | - D. Sustaita
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Rd., San Marcos, CA 92096, USA
| | - P. Clausen
- School of Engineering, University of Newcastle, NSW 2308 Newcastle, Australia
| | - R. P. Scofield
- Natural History, Canterbury Museum, Rolleston Avenue, 8013 Christchurch, New Zealand
| | - G. Sansalone
- School of Environmental and Rural Science, University of New England, Earth Sciences Building, NSW 2351 Armidale, Australia
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25
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Liu H, Ouyang D, Wang J, Lei C, Shi W, Gilliam T, Liu J, Li Y, Chopra N. Chemical Vapor Deposition Mechanism of Graphene-Encapsulated Au Nanoparticle Heterostructures and Their Plasmonics. ACS Appl Mater Interfaces 2021; 13:58134-58143. [PMID: 34807555 DOI: 10.1021/acsami.1c16608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Direct encapsulation of graphene shells on noble metal nanoparticles via chemical vapor deposition (CVD) has been recently reported as a unique way to design and fabricate new plasmonic heterostructures. But currently, the fundamental nature of the growth mechanism of graphene layers on metal nanostructures is still unknown. Herein, we report a systematic investigation on the CVD growth of graphene-encapsulated Au nanoparticles (Au@G) by combining an experimental parameter study and theoretical modeling. We studied the effect of growth temperature, duration, hydrocarbon precursor concentration, and extent of reducing (H2) environment on the morphology of the products. In addition, the influence of plasma oxidation conditions for the surface oxidation of gold nanoparticles on the graphene shell growth is evaluated in combination with thermodynamic calculations. We find that these parameters critically aid in the evolution of graphene shells around gold nanoparticles and allow for controlling shell thickness, graphene shell quality and morphology, and hybrid nanoparticle diameter. An optimized condition including the growth temperature of ∼675 °C, duration of 30 min, and xylene feed rate of ∼10 mL/h with 10% H2/Ar carrier gas was finally obtained for the best morphology evolution. We further performed finite-element analysis (FEA) simulations to understand the equivalent von Mises stress distribution and discrete dipolar approximation (DDA) calculation to reveal the optical properties of such new core-shell heterostructures. This study brings new insight to the nature of CVD mechanism of Au@G and might help guiding their controlled growth and future design and application in plasmonic applications.
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Affiliation(s)
- Heguang Liu
- School of Materials Science and Engineering, Xi'an University of Technology, Xi'an, Shaanxi 710048, China
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China
| | - Decai Ouyang
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Jing Wang
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Chao Lei
- School of Materials Science and Engineering, Xi'an University of Technology, Xi'an, Shaanxi 710048, China
| | - Wenwu Shi
- Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, Alabama 35401, United States
| | - Todd Gilliam
- Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, Alabama 35401, United States
| | - Jianxi Liu
- State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi'an 710072, China
| | - Yuan Li
- State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Nitin Chopra
- Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, Alabama 35401, United States
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26
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Mousavi J. S. SM, Faghihi D, Sommer K, Bhurwani MMS, Patel TR, Santo B, Waqas M, Ionita C, Levy EI, Siddiqui AH, Tutino VM. Realistic computer modelling of stent retriever thrombectomy: a hybrid finite-element analysis-smoothed particle hydrodynamics model. J R Soc Interface 2021; 18:20210583. [PMID: 34905967 PMCID: PMC8672072 DOI: 10.1098/rsif.2021.0583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 11/22/2021] [Indexed: 01/11/2023] Open
Abstract
Stent retriever thrombectomy is a pre-eminent treatment modality for large vessel ischaemic stroke. Simulation of thrombectomy could help understand stent and clot mechanics in failed cases and provide a digital testbed for the development of new, safer devices. Here, we present a novel, in silico thrombectomy method using a hybrid finite-element analysis (FEA) and smoothed particle hydrodynamics (SPH). Inspired by its biological structure and components, the blood clot was modelled with the hybrid FEA-SPH method. The Solitaire self-expanding stent was parametrically reconstructed from micro-CT imaging and was modelled as three-dimensional finite beam elements. Our simulation encompassed all steps of mechanical thrombectomy, including stent packaging, delivery and self-expansion into the clot, and clot extraction. To test the feasibility of our method, we simulated clot extraction in simple straight vessels. This was compared against in vitro thrombectomies using the same stent, vessel geometry, and clot size and composition. Comparisons with benchtop tests indicated that our model was able to accurately simulate clot deflection and penetration of stent wires into the clot, the relative movement of the clot and stent during extraction, and clot fragmentation/embolus formation. In this study, we demonstrated that coupling FEA and SPH techniques could realistically model stent retriever thrombectomy.
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Affiliation(s)
- S. Mostafa Mousavi J. S.
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Danial Faghihi
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Kelsey Sommer
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Mohammad M. S. Bhurwani
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Tatsat R. Patel
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Briana Santo
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, NY 14203, USA
| | - Muhammad Waqas
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Ciprian Ionita
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Biomedical Engineering, University at Buffalo, Buffalo, NY 14203, USA
| | - Elad I. Levy
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY 14203, USA
| | - Adnan H. Siddiqui
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY 14203, USA
| | - Vincent M. Tutino
- Canon Stroke and Vascular Research Center, University at Buffalo, Buffalo, NY 14203, USA
- Department of Mechanical and Aerospace Engineering, University at Buffalo, Buffalo, NY 14203, USA
- Department of Neurosurgery, University at Buffalo, Buffalo, NY 14203, USA
- Department of Pathology and Anatomical Sciences, University at Buffalo, Buffalo, NY 14203, USA
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27
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Cook RW, Vazzana A, Sorrentino R, Benazzi S, Smith AL, Strait DS, Ledogar JA. The cranial biomechanics and feeding performance of Homo floresiensis. Interface Focus 2021; 11:20200083. [PMID: 34938433 PMCID: PMC8361579 DOI: 10.1098/rsfs.2020.0083] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2021] [Indexed: 11/12/2022] Open
Abstract
Homo floresiensis is a small-bodied hominin from Flores, Indonesia, that exhibits plesiomorphic dentognathic features, including large premolars and a robust mandible, aspects of which have been considered australopith-like. However, relative to australopith species, H. floresiensis exhibits reduced molar size and a cranium with diminutive midfacial dimensions similar to those of later Homo, suggesting a reduction in the frequency of forceful biting behaviours. Our study uses finite-element analysis to examine the feeding biomechanics of the H. floresiensis cranium. We simulate premolar (P3) and molar (M2) biting in a finite-element model (FEM) of the H. floresiensis holotype cranium (LB1) and compare the mechanical results with FEMs of chimpanzees, modern humans and a sample of australopiths (MH1, Sts 5, OH5). With few exceptions, strain magnitudes in LB1 resemble elevated levels observed in modern Homo. Our analysis of LB1 suggests that H. floresiensis could produce bite forces with high mechanical efficiency, but was subject to tensile jaw joint reaction forces during molar biting, which perhaps constrained maximum postcanine bite force production. The inferred feeding biomechanics of H. floresiensis closely resemble modern humans, suggesting that this pattern may have been present in the last common ancestor of Homo sapiens and H. floresiensis.
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Affiliation(s)
- Rebecca W Cook
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
| | - Antonino Vazzana
- Department of Cultural Heritage, University of Bologna, Bologna, Italy
| | - Rita Sorrentino
- Department of Cultural Heritage, University of Bologna, Bologna, Italy.,Department of Biological, Geological, and Environmental Sciences, University of Bologna, Bologna, Italy
| | - Stefano Benazzi
- Department of Cultural Heritage, University of Bologna, Bologna, Italy.,Department of Human Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Amanda L Smith
- Department of Anatomy, Pacific Northwest University of Health Sciences, Yakima, WA, USA
| | - David S Strait
- Department of Anthropology, Washington University in St Louis, St Louis, MO, USA
| | - Justin A Ledogar
- Department of Evolutionary Anthropology, Duke University, Durham, NC, USA
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28
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Brumund P, Reyes-Herrera J, Morawe C, Dufrane T, Isern H, Brochard T, Sánchez Del Río M, Detlefs C. Thermal optimization of a high-heat-load double-multilayer monochromator. J Synchrotron Radiat 2021; 28:1423-1436. [PMID: 34475290 DOI: 10.1107/s160057752100758x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/24/2021] [Indexed: 06/13/2023]
Abstract
Finite-element analysis is used to study the thermal deformation of a multilayer mirror due to the heat load from the undulator beam at a low-emittance synchrotron source, specifically the ESRF-EBS upgrade beamline EBSL-2. The energy bandwidth of the double-multilayer monochromator is larger than that of the relevant undulator harmonic, such that a considerable portion of the heat load is reflected. Consequently, the absorbed power is non-uniformly distributed on the surface. The geometry of the multilayer substrate is optimized to minimize thermally induced slope errors. We distinguish between thermal bending with constant curvature that leads to astigmatic focusing or defocusing and residual slope errors. For the EBSL-2 system with grazing angles θ between 0.2 and 0.4°, meridional and sagittal focal lengths down to 100 m and 2000 m, respectively, are found. Whereas the thermal bending can be tuned by varying the depth of the `smart cut', it is found that the geometry has little effect on the residual slope errors. In both planes they are 0.1-0.25 µrad. In the sagittal direction, however, the effect on the beam is drastically reduced by the `foregiveness factor', sin(θ). Optimization without considering the reflected heat load yields an incorrect depth of the `smart cut'. The resulting meridional curvature in turn leads to parasitic focal lengths of the order of 100 m.
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Affiliation(s)
- Philipp Brumund
- ESRF - The European Synchrotron, 38043 Grenoble Cedex 9, France
| | | | | | - Thomas Dufrane
- ESRF - The European Synchrotron, 38043 Grenoble Cedex 9, France
| | - Helena Isern
- ESRF - The European Synchrotron, 38043 Grenoble Cedex 9, France
| | | | | | - Carsten Detlefs
- ESRF - The European Synchrotron, 38043 Grenoble Cedex 9, France
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29
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Lewandowski K, Kaczmarczyk Ł, Athanasiadis I, Marshall JF, Pearce CJ. A computational framework for crack propagation in spatially heterogeneous materials. Philos Trans A Math Phys Eng Sci 2021; 379:20200291. [PMID: 34148414 DOI: 10.1098/rsta.2020.0291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/06/2021] [Indexed: 06/12/2023]
Abstract
This paper presents a mathematical formulation and numerical modelling framework for brittle crack propagation in heterogeneous elastic solids. Such materials are present in both natural and engineered scenarios. The formulation is developed in the framework of configurational mechanics and solved numerically using the finite-element method. We show the methodology previously established for homogeneous materials without the need for any further assumptions. The proposed model is based on the assumption of maximal dissipation of energy and uses the Griffith criterion; we show that this is sufficient to predict crack propagation in brittle heterogeneous materials, with spatially varying Young's modulus and fracture energy. Furthermore, we show that the crack path trajectory orientates itself such that it is always subject to Mode-I. The configurational forces and fracture energy release rate are both expressed exclusively in terms of nodal quantities, avoiding the need for post-processing and enabling a fully implicit formulation for modelling the evolving crack front and creation of new crack surfaces. The proposed formulation is verified and validated by comparing numerical results with both analytical solutions and experimental results. Both the predicted crack path and load-displacement response show very good agreement with experiments where the crack path was independent of material heterogeneity for those cases. Finally, the model is successfully used to consider the real and challenging scenario of fracture of an equine bone, with spatially varying material properties obtained from CT scanning. This article is part of a discussion meeting issue 'A cracking approach to inventing new tough materials: fracture stranger than friction'.
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Affiliation(s)
- Karol Lewandowski
- Glasgow Computational Engineering Centre, The James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
| | - Łukasz Kaczmarczyk
- Glasgow Computational Engineering Centre, The James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
| | - Ignatios Athanasiadis
- Glasgow Computational Engineering Centre, The James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
| | - John F Marshall
- Weipers Centre Equine Hospital, School of Veterinary Medicine, University of Glasgow, Glasgow G61 1QH, UK
| | - Chris J Pearce
- Glasgow Computational Engineering Centre, The James Watt School of Engineering, University of Glasgow, Glasgow G12 8QQ, UK
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30
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Li L, Guo C, Xu S, Guo H, Yu P, Liu L, Tian J. Mathematical Model and microCT-Based Kinematic Analysis of the Rostrum Mouthparts in Cyrtotrachelus buqueti Guer (Coleoptera: Curculionidae). Microsc Microanal 2021; 27:860-877. [PMID: 33993901 DOI: 10.1017/s143192762100043x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
To uncover the chewing mechanism of Cyrtotrachelus buqueti Guer, a mathematical model was created and a kinematic analysis of its rostrum mouthparts was conducted for, to our knowledge, the first time. To reduce noise and improve the quality of scanning electron micrographs of the weevil's mouthparts, nonlocal means and integral nonlocal means algorithms were proposed. Additionally, based on a comparison and analysis of five classical edge detection algorithms, a multiscale edge detection algorithm based on the B-spline wavelet was used to obtain the boundaries of structural features. The least squares method was used to analyze the data of the mouthparts to fit the mathematical model and fitted curves were obtained using Gaussian equations. The results show that curvature and concave-convex variations of the weevil's mouthparts can highlight fluctuations in friction effects when it chews bamboo shoots, which is helpful in preventing debris from bamboo shoots or other debris from sticking to the mouthpart surfaces. Moreover, this paper highlights the utility of micro-computed tomography (microCT) for three-dimensional (3D) reconstruction and a flowchart is suggested. The reconstructed slices were 9.0 μm thick and an accurate 3D rendered model was obtained from a series of microCT slices. Finally, a real model of the rostrum mouthparts was analyzed using finite-element analysis. The results provide a biological template for the design of a novel bionic drilling mechanism.
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Affiliation(s)
- Longhai Li
- School of Mechanical and Electrical Engineering, Xuzhou University of Technology, Xuzhou221018, China
| | - Ce Guo
- Institute of Bio-inspired Structure and Surface Engineering, College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing210016, China
| | - Shun Xu
- Key Laboratory of Bionic Engineering (Ministry of Education, China), College of Biological and Agricultural Engineering, Jilin University, Changchun130025, China
| | - Huafeng Guo
- School of Mechanical and Electrical Engineering, Xuzhou University of Technology, Xuzhou221018, China
| | - Ping Yu
- School of Mechanical and Electrical Engineering, Xuzhou University of Technology, Xuzhou221018, China
| | - Lei Liu
- School of Mechanical and Electrical Engineering, Xuzhou University of Technology, Xuzhou221018, China
| | - Jing Tian
- School of Mechanical and Electrical Engineering, Xuzhou University of Technology, Xuzhou221018, China
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31
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Bates KT, Wang L, Dempsey M, Broyde S, Fagan MJ, Cox PG. Back to the bones: do muscle area assessment techniques predict functional evolution across a macroevolutionary radiation? J R Soc Interface 2021; 18:20210324. [PMID: 34283941 PMCID: PMC8292018 DOI: 10.1098/rsif.2021.0324] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Measures of attachment or accommodation area on the skeleton are a popular means of rapidly generating estimates of muscle proportions and functional performance for use in large-scale macroevolutionary studies. Herein, we provide the first evaluation of the accuracy of these muscle area assessment (MAA) techniques for estimating muscle proportions, force outputs and bone loading in a comparative macroevolutionary context using the rodent masticatory system as a case study. We find that MAA approaches perform poorly, yielding large absolute errors in muscle properties, bite force and particularly bone stress. Perhaps more fundamentally, these methods regularly fail to correctly capture many qualitative differences between rodent morphotypes, particularly in stress patterns in finite-element models. Our findings cast doubts on the validity of these approaches as means to provide input data for biomechanical models applied to understand functional transitions in the fossil record, and perhaps even in taxon-rich statistical models that examine broad-scale macroevolutionary patterns. We suggest that future work should go back to the bones to test if correlations between attachment area and muscle size within homologous muscles across a large number of species yield strong predictive relationships that could be used to deliver more accurate predictions for macroevolutionary and functional studies.
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Affiliation(s)
- Karl T Bates
- Department of Musculoskeletal Biology, Institute of Life Course and Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool L7 8TX, UK
| | - Linjie Wang
- Department of Engineering, University of Hull, Hull HU6 7RX, UK
| | - Matthew Dempsey
- Department of Musculoskeletal Biology, Institute of Life Course and Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool L7 8TX, UK
| | - Sarah Broyde
- Department of Musculoskeletal Biology, Institute of Life Course and Medical Sciences, University of Liverpool, The William Henry Duncan Building, 6 West Derby Street, Liverpool L7 8TX, UK
| | - Michael J Fagan
- Department of Engineering, University of Hull, Hull HU6 7RX, UK
| | - Philip G Cox
- Department of Archaeology, University of York, PalaeoHub, Wentworth Way, Heslington, York YO10 5DD, UK.,Hull York Medical School, University of York, Heslington, York YO10 5DD, UK
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32
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Pasta S, Cannata S, Gentile G, Agnese V, Raffa GM, Pilato M, Gandolfo C. Transcatheter Heart Valve Implantation in Bicuspid Patients with Self-Expanding Device. Bioengineering (Basel) 2021; 8:91. [PMID: 34356198 DOI: 10.3390/bioengineering8070091] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 06/22/2021] [Accepted: 06/22/2021] [Indexed: 11/30/2022] Open
Abstract
Bicuspid aortic valve (BAV) patients are conventionally not treated by transcathether aortic valve implantation (TAVI) because of anatomic constraint with unfavorable outcome. Patient-specific numerical simulation of TAVI in BAV may predict important clinical insights to assess the conformability of the transcathether heart valves (THV) implanted on the aortic root of members of this challenging patient population. We aimed to develop a computational approach and virtually simulate TAVI in a group of n.6 stenotic BAV patients using the self-expanding Evolut Pro THV. Specifically, the structural mechanics were evaluated by a finite-element model to estimate the deformed THV configuration in the oval bicuspid anatomy. Then, a fluid–solid interaction analysis based on the smoothed-particle hydrodynamics (SPH) technique was adopted to quantify the blood-flow patterns as well as the regions at high risk of paravalvular leakage (PVL). Simulations demonstrated a slight asymmetric and elliptical expansion of the THV stent frame in the BAV anatomy. The contact pressure between the luminal aortic root surface and the THV stent frame was determined to quantify the device anchoring force at the level of the aortic annulus and mid-ascending aorta. At late diastole, PVL was found in the gap between the aortic wall and THV stent frame. Though the modeling framework was not validated by clinical data, this study could be considered a further step towards the use of numerical simulations for the assessment of TAVI in BAV, aiming at understanding patients not suitable for device implantation on an anatomic basis.
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Abstract
Background. There has been historical debate as to whether the distal tibiofibular syndesmosis can be overtightened during operative fixation. We used finite-element analysis to determine if overtightening of syndesmotic screws can cause widening of the lateral gutter clear space in the ankle joint. Methods. A 3D finite-element model was constructed and analyzed using geometries from a computed tomography scan of a cadaveric lower leg. Starting 2 cm from the plafond, screw fixation was simulated at 5-mm increments to a distance of 5 cm from the plafond. The fibula was compressed 2 mm toward the tibia at each interval, and the change in distance between the lateral talus and distal fibula was measured. Results. Medial deflection of the fibula resulted in widening of the lateral clear space, which was proportional to the amount of deflection. The effect increased as screws were placed closer to the plafond, with 1.5 mm of widening at 2 cm (0.76 mm/mm) versus 0.7 mm at 5 cm (0.34 mm/mm). Conclusion. Our finite-element model demonstrated that overtightening of the distal tibiofibular syndesmosis with medial fibular displacement can cause widening of the lateral clear space. Clinical relevance. The results suggest that screws placed farther from the plafond widen the lateral clear space to a lesser degree, which may be advantageous during surgical fixation to prevent clear space widening and increased tibiotalar contact forces.Levels of Evidence: Level I.
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Affiliation(s)
- Nicholas G Vance
- Sports Orthopedic + Spine, Jackson, Tennessee (NGV).,Robert Vance Consulting, PLLC, Arlington, Texas (RCV).,Wake Forest School of Medicine, Winston-Salem, North Carolina (WTC).,Department of Orthopaedic Surgery and Rehabilitation, The University of Texas Medical Branch, Galveston, Texas (VKP)
| | - Robert C Vance
- Sports Orthopedic + Spine, Jackson, Tennessee (NGV).,Robert Vance Consulting, PLLC, Arlington, Texas (RCV).,Wake Forest School of Medicine, Winston-Salem, North Carolina (WTC).,Department of Orthopaedic Surgery and Rehabilitation, The University of Texas Medical Branch, Galveston, Texas (VKP)
| | - William T Chandler
- Sports Orthopedic + Spine, Jackson, Tennessee (NGV).,Robert Vance Consulting, PLLC, Arlington, Texas (RCV).,Wake Forest School of Medicine, Winston-Salem, North Carolina (WTC).,Department of Orthopaedic Surgery and Rehabilitation, The University of Texas Medical Branch, Galveston, Texas (VKP)
| | - Vinod K Panchbhavi
- Sports Orthopedic + Spine, Jackson, Tennessee (NGV).,Robert Vance Consulting, PLLC, Arlington, Texas (RCV).,Wake Forest School of Medicine, Winston-Salem, North Carolina (WTC).,Department of Orthopaedic Surgery and Rehabilitation, The University of Texas Medical Branch, Galveston, Texas (VKP)
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34
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Isakhani H, Xiong C, Chen W, Yue S. Towards locust-inspired gliding wing prototypes for micro aerial vehicle applications. R Soc Open Sci 2021; 8:202253. [PMID: 34234953 PMCID: PMC8242835 DOI: 10.1098/rsos.202253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 05/12/2021] [Indexed: 06/13/2023]
Abstract
In aviation, gliding is the most economical mode of flight explicitly appreciated by natural fliers. They achieve it by high-performance wing structures evolved over millions of years in nature. Among other prehistoric beings, locust is a perfect example of such natural glider capable of endured transatlantic flights that could inspire a practical solution to achieve similar capabilities on micro aerial vehicles. An investigation in this study demonstrates the effects of haemolymph on the flexibility of several flying insect wings proving that many species exist with further simplistic yet well-designed wing structures. However, biomimicry of such aerodynamic and structural properties is hindered by the limitations of modern as well as conventional fabrication technologies in terms of availability and precision, respectively. Therefore, here we adopt finite-element analysis to investigate the manufacturing-worthiness of a three-dimensional digitally reconstructed locust wing, and propose novel combinations of economical and readily available manufacturing methods to develop the model into prototypes that are structurally similar to their counterparts in nature while maintaining the optimum gliding ratio previously obtained in the aerodynamic simulations. The former is assessed here via an experimental analysis of the flexural stiffness and maximum deformation rate as EI s = 1.34 × 10-4 Nm2, EI c = 5.67 × 10-6 Nm2 and greater than 148.2%, respectively. Ultimately, a comparative study of the mechanical properties reveals the feasibility of each prototype for gliding micro aerial vehicle applications.
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Affiliation(s)
- Hamid Isakhani
- The Computational Intelligence Lab (CIL), School of Computer Science, University of Lincoln, LN6 7TS Lincoln, UK
| | - Caihua Xiong
- The State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
| | - Wenbin Chen
- The State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, People’s Republic of China
| | - Shigang Yue
- The Computational Intelligence Lab (CIL), School of Computer Science, University of Lincoln, LN6 7TS Lincoln, UK
- Machine Life and Intelligence Research Centre, Guangzhou University, Guangzhou 510006, People’s Republic of China
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Bicknell RDC, Holmes JD, Edgecombe GD, Losso SR, Ortega-Hernández J, Wroe S, Paterson JR. Biomechanical analyses of Cambrian euarthropod limbs reveal their effectiveness in mastication and durophagy. Proc Biol Sci 2021; 288:20202075. [PMID: 33499790 DOI: 10.1098/rspb.2020.2075] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Durophagy arose in the Cambrian and greatly influenced the diversification of biomineralized defensive structures throughout the Phanerozoic. Spinose gnathobases on protopodites of Cambrian euarthropod limbs are considered key innovations for shell-crushing, yet few studies have demonstrated their effectiveness with biomechanical models. Here we present finite-element analysis models of two Cambrian trilobites with prominent gnathobases-Redlichia rex and Olenoides serratus-and compare these to the protopodites of the Cambrian euarthropod Sidneyia inexpectans and the modern American horseshoe crab, Limulus polyphemus. Results show that L. polyphemus, S. inexpectans and R. rex have broadly similar microstrain patterns, reflecting effective durophagous abilities. Conversely, low microstrain values across the O. serratus protopodite suggest that the elongate gnathobasic spines transferred minimal strain, implying that this species was less well-adapted to masticate hard prey. These results confirm that Cambrian euarthropods with transversely elongate protopodites bearing short, robust gnathobasic spines were likely durophages. Comparatively, taxa with shorter protopodites armed with long spines, such as O. serratus, were more likely restricted to a soft food diet. The prevalence of Cambrian gnathobase-bearing euarthropods and their various feeding specializations may have accelerated the development of complex trophic relationships within early animal ecosystems, especially the 'arms race' between predators and biomineralized prey.
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Affiliation(s)
- Russell D C Bicknell
- Palaeoscience Research Centre, School of Environmental & Rural Science University of New England, Armidale, NSW 2351, Australia.,Function, Evolution and Anatomy Research Lab, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - James D Holmes
- School of Biological Sciences, University of Adelaide, North Terrace, Adelaide, SA 5005, Australia
| | - Gregory D Edgecombe
- Department of Earth Sciences, The Natural History Museum, London SW7 5BD, UK
| | - Sarah R Losso
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Javier Ortega-Hernández
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA
| | - Stephen Wroe
- Palaeoscience Research Centre, School of Environmental & Rural Science University of New England, Armidale, NSW 2351, Australia.,Function, Evolution and Anatomy Research Lab, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - John R Paterson
- Palaeoscience Research Centre, School of Environmental & Rural Science University of New England, Armidale, NSW 2351, Australia
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36
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Ugarte OM, Gialain IO, de Carvalho NM, Fukuoka GL, Ballester RY, Cattaneo PM, Roscoe MG, Meira JBC. Can maxilla and mandible bone quality explain differences in orthodontic mini-implant failures? Biomater Investig Dent 2021; 8:1-9. [PMID: 33521649 PMCID: PMC7808375 DOI: 10.1080/26415275.2020.1863155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Abstract
Purpose: This study aimed to compare the risk of orthodontic mini-implant (OMI) failure between maxilla and mandible. A critical analysis of finite-element studies was used to explain the contradiction of the greatest clinical success for OMIs placed in the maxilla, despite the higher quality bone of mandible. Materials and Methods: Four tridimensional FE models were built, simulating an OMI inserted in a low-dense maxilla, control maxilla, control mandible, and high-dense mandible. A horizontal force was applied to simulate an anterior retraction of 2 N (clinical scenario) and 10 N (overloading condition). The intra-bone OMI displacement and the major principal bone strains were used to evaluate the risk of failure due to insufficient primary stability or peri-implant bone resorption. Results: The OMI displacement was far below the 50–100 µm threshold, suggesting that the primary stability would be sufficient in all models. However, the maxilla was more prone to lose its stability due to overload conditions, especially in the low-dense condition, in which major principal bone strains surpassed the pathologic bone resorption threshold of 3000 µstrain. Conclusions: The differences in orthodontic mini-implant failures cannot be explained by maxilla and mandible bone quality in finite-element analysis that does not incorporate the residual stress due to OMI insertion.
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Affiliation(s)
- Omar Melendres Ugarte
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
| | - Ivan Onone Gialain
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
| | - Naor Maldonado de Carvalho
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
| | - Gisele Lie Fukuoka
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
| | - Rafael Yague Ballester
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
| | - Paolo Maria Cattaneo
- Department of Dentistry, Section of Orthodontics, Aarhus University, Aarhus, Denmark
| | - Marina Guimarães Roscoe
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
| | - Josete Barbosa Cruz Meira
- School of Dentistry, Department of Biomaterials and Oral Biology, University of São Paulo, São Paulo, Brazil
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37
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Nicolaidou E, Hill TL, Neild SA. Indirect reduced-order modelling: using nonlinear manifolds to conserve kinetic energy. Proc Math Phys Eng Sci 2020; 476:20200589. [PMID: 33362422 DOI: 10.1098/rspa.2020.0589] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Accepted: 10/21/2020] [Indexed: 11/12/2022] Open
Abstract
Nonlinear dynamic analysis of complex engineering structures modelled using commercial finite element (FE) software is computationally expensive. Indirect reduced-order modelling strategies alleviate this cost by constructing low-dimensional models using a static solution dataset from the FE model. The applicability of such methods is typically limited to structures in which (a) the main source of nonlinearity is the quasi-static coupling between transverse and in-plane modes (i.e. membrane stretching); and (b) the amount of in-plane displacement is limited. We show that the second requirement arises from the fact that, in existing methods, in-plane kinetic energy is assumed to be negligible. For structures such as thin plates and slender beams with fixed/pinned boundary conditions, this is often reasonable, but in structures with free boundary conditions (e.g. cantilever beams), this assumption is violated. Here, we exploit the concept of nonlinear manifolds to show how the in-plane kinetic energy can be accounted for in the reduced dynamics, without requiring any additional information from the FE model. This new insight enables indirect reduction methods to be applied to a far wider range of structures while maintaining accuracy to higher deflection amplitudes. The accuracy of the proposed method is validated using an FE model of a cantilever beam.
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Affiliation(s)
- Evangelia Nicolaidou
- Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR, UK
| | - Thomas L Hill
- Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR, UK
| | - Simon A Neild
- Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR, UK
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38
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Abstract
The shells of ammonoid cephalopods are among the most recognizable fossils, whose fractally folded, internal walls (septa) have inspired many hypotheses on their adaptive value. The enduring explanation for their iterative evolution is that they strengthen the shell against pressure at increasing water depths. The fossil record does not definitively support this idea and much of the theoretical mechanical work behind it has suffered from inaccurate testing geometries and conflicting results. By using a different set of mathematical methods compared with previous studies, I generate a system of finite-element models that explore how different parameters affect the shell's response to water pressure. Increasing the number of initial folds of the septa ultimately has little to no effect on the resulting stress in the shell wall or the septum itself. The introduction of higher-order folds does reduce the tensile stress in the shell wall; however, this is coupled with a higher rate of increase of tensile stress in the septum itself. These results reveal that the increase in complexity should not be expected to have a significant effect on the shell's strength and suggests that the evolution of ammonitic septa does not reflect a persistent trend towards deeper-water habitats.
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Affiliation(s)
- Robert Lemanis
- B CUBE-Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany
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39
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Mader A, Langer M, Knippers J, Speck O. Learning from plant movements triggered by bulliform cells: the biomimetic cellular actuator. J R Soc Interface 2020; 17:20200358. [PMID: 32842889 PMCID: PMC7482577 DOI: 10.1098/rsif.2020.0358] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/05/2020] [Indexed: 01/18/2023] Open
Abstract
Within the framework of a biomimetic top-down approach, our study started with the technical question of the development of a hinge-free and compliant actuator inspired by plant movements. One meaningful biological concept generator was the opening and closing movements of the leaf halves of grasses. Functional morphological investigations were carried out on the selected model plant Sesleria nitida. The results formed the basis for further clarifying the functional movement principle with a particular focus on the role of turgor changes in bulliform cells on kinetic amplification. All findings gained from the investigations of the biological model were incorporated into a finite-element analysis, as a prerequisite for the development of a pneumatic cellular actuator. The first prototype consisted of a row of single cells positioned on a plate. The cells were designed in such a way that the entire structure bent when the pneumatic pressure applied to each individual cell was increased. The pneumatic cellular actuator thus has the potential for applications on an architectural scale. It has subsequently been integrated into the midrib of the facade shading system Flectofold in which the bending of its midrib controls the hoisting of its wings.
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Affiliation(s)
- Anja Mader
- Institute of Building Structures and Structural Design (ITKE), University of Stuttgart, Stuttgart, Germany
| | - Max Langer
- Plant Biomechanics Group, Botanic Garden, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Jan Knippers
- Institute of Building Structures and Structural Design (ITKE), University of Stuttgart, Stuttgart, Germany
| | - Olga Speck
- Plant Biomechanics Group, Botanic Garden, Faculty of Biology, University of Freiburg, Freiburg, Germany
- Cluster of Excellence livMatS @ FIT—Freiburg Center for Interactive Materials and Bioinspired Technologies, University of Freiburg, Freiburg, Germany
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40
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Abstract
The halteres of flies are mechanosensory organs that serve a crucial role in the control of agile flight, providing sensory input for rapid course corrections to perturbations. Derived from hind wings, halteres are actively flapped and are thus subject to a variety of inertial forces as the fly undergoes complex flight trajectories. Previous analyses of halteres modelled them as a point mass, showing that Coriolis forces lead to subtle deflections orthogonal to the plane of flapping. By design, these models could not consider the effects of force gradients associated with a mass distribution, nor could they reveal three-dimensional spatio-temporal patterns of strain that result from those forces. In addition, diversity in the geometry of halteres, such as shape and asymmetries, could not be simply modelled with a point mass on a massless rod. To study the effects of mass distributions and asymmetries, we examine the haltere subject to both flapping and body rotations using three-dimensional finite-element simulations. We focus on a set of simplified geometries, in which we vary the stalk and bulb shape. We find that haltere mass distribution gives rise to two unreported deformation modes: (i) halteres twist with a magnitude that strongly depends on stalk and bulb geometry and (ii) halteres with an asymmetric mass distribution experience out-of-plane bending due to centrifugal forces, independent of body rotation. Since local strains at the base of the haltere drive deformations of mechanosensory neurons, we combined measured neural encoding mechanisms with our structural analyses to predict the spatial and temporal patterns of neural activity. This activity depends on both the flapping and rotation dynamics, and we show how the timing of neural activity is a viable mechanism for rotation-rate encoding. Our results provide new insights in haltere dynamics and show the viability for timing-based encoding of fly body rotations by halteres.
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Affiliation(s)
- T L Mohren
- 1 Department of Mechanical Engineering, University of Washington , Seattle, WA , USA
| | - T L Daniel
- 1 Department of Mechanical Engineering, University of Washington , Seattle, WA , USA.,2 Department of Biology, University of Washington , Seattle, WA , USA
| | - A L Eberle
- 1 Department of Mechanical Engineering, University of Washington , Seattle, WA , USA
| | - P G Reinhall
- 1 Department of Mechanical Engineering, University of Washington , Seattle, WA , USA
| | - J L Fox
- 3 Department of Biology, Case Western Reserve University , Cleveland, OH , USA
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41
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Abstract
Cephalopods transformed the molluscan shell into a buoyancy device that must be strong enough to resist external water pressure. Historically, unique features of the shell have been interpreted on the basis that the strength of the shell presents a hard limit on maximum habitat depth. One such feature is the mural flap, which is a semi-prismatic layer deposited on the inner surface of some coleoid septa that has been suggested to strengthen the shell and permit colonization of deeper waters. We test this hypothesis by constructing finite-element models that show how mural modifications affect the response of the shell to hydrostatic pressure. The mural flaps are found to have no notable structural function. Another mural modification discovered here is the adapical ridge flap that initially seemed to have a potential function in shifting peak stress away from the attachment site of the septum; however, the irregular distribution of this feature casts any functional interpretation in doubt. Ecological separation of belemnites and decabrachians is likely not mediated by the presence/absence of mural flaps. This work illustrates a potential caveat that not all unique septal features formed in response to increasing hydrostatic pressure and deeper habitats.
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Affiliation(s)
- Robert Lemanis
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Deborah Stier
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Igor Zlotnikov
- B CUBE - Center for Molecular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Paul Zaslansky
- Department for Restorative and Preventive Dentistry, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Dirk Fuchs
- Bayerische Staatssammlung für Paläntologie und Geologie, Munich, Germany
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42
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Müller R, Henss A, Kampschulte M, Rohnke M, Langheinrich AC, Heiss C, Janek J, Voigt A, Wilke HJ, Ignatius A, Herfurth J, El Khassawna T, Deutsch A. Analysis of microscopic bone properties in an osteoporotic sheep model: a combined biomechanics, FE and ToF-SIMS study. J R Soc Interface 2020; 16:20180793. [PMID: 30958193 DOI: 10.1098/rsif.2018.0793] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The present study deals with the characterization of bone quality in a sheep model of postmenopausal osteoporosis. Sheep were sham operated ( n = 7), ovariectomized ( n = 6), ovariectomized and treated with deficient diet ( n = 8) or ovariectomized, treated with deficient diet and glucocorticoid injections ( n = 7). The focus of the study is on the microscopic properties at tissue level. Microscopic mechanical properties of osteoporotic bone were evaluated by a combination of biomechanical testing and mathematical modelling. Sample stiffness and strength were determined by compression tests and finite-element analysis of stress states was conducted. From this, an averaged microscopic Young's modulus at tissue level was determined. Trabecular structure as well as mineral and collagen distribution in samples of sheep vertebrae were analysed by micro-computed tomography and time-of-flight secondary ion mass spectrometry. In the osteoporotic sheep model, a disturbed fibril structure in the triple treated group was observed, but bone loss only occurred in form of reduced trabecular number and thickness and cortical decline, while quality of the residual bone was preserved. The preserved bone tissue properties in the osteoporotic sheep model allowed for an estimation of bone strength which behaves similar to the human case.
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Affiliation(s)
- R Müller
- 1 Centre for Information Services and High Performance Computing , TU Dresden, 01062 Dresden , Germany
| | - A Henss
- 2 Institute of Physical Chemistry and Center for Materials Research (ZfM/LaMa), Justus-Liebig University of Giessen , 35392 Giessen , Germany
| | - M Kampschulte
- 4 Department of Diagnostic and Interventional Radiology, University Hospital of Giessen-Marburg , 35392 Giessen , Germany
| | - M Rohnke
- 2 Institute of Physical Chemistry and Center for Materials Research (ZfM/LaMa), Justus-Liebig University of Giessen , 35392 Giessen , Germany
| | - A C Langheinrich
- 6 Department of Diagnostic and Interventional Radiology, BG Trauma Hospital , 60389 Frankfurt/Main , Germany
| | - C Heiss
- 3 Experimental Trauma Surgery, Justus-Liebig University of Giessen , 35392 Giessen , Germany.,5 Department of Trauma, Hand, and Reconstructive Surgery, University Hospital of Giessen-Marburg , Giessen , Germany
| | - J Janek
- 2 Institute of Physical Chemistry and Center for Materials Research (ZfM/LaMa), Justus-Liebig University of Giessen , 35392 Giessen , Germany
| | - A Voigt
- 8 Institute of Scientific Computing , TU Dresden, 01062 Dresden , Germany
| | - H J Wilke
- 7 Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre, Ulm University-Medical Centre , Ulm , Germany
| | - A Ignatius
- 7 Institute of Orthopaedic Research and Biomechanics, Trauma Research Centre, Ulm University-Medical Centre , Ulm , Germany
| | - J Herfurth
- 3 Experimental Trauma Surgery, Justus-Liebig University of Giessen , 35392 Giessen , Germany
| | - T El Khassawna
- 3 Experimental Trauma Surgery, Justus-Liebig University of Giessen , 35392 Giessen , Germany
| | - A Deutsch
- 1 Centre for Information Services and High Performance Computing , TU Dresden, 01062 Dresden , Germany
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43
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Zhou R, Pang KH, Bisht A, Roy A, Suwas S, Silberschmidt VV. Modelling strain localization in Ti-6Al-4V at high loading rate: a phenomenological approach. Philos Trans A Math Phys Eng Sci 2020; 378:20190105. [PMID: 31760906 PMCID: PMC6894524 DOI: 10.1098/rsta.2019.0105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 06/10/2019] [Indexed: 06/10/2023]
Abstract
A phenomenological approach, based on a combination of a damage mechanism and a crystal plasticity model, is proposed to model a process of strain localization in Ti-6AI-4V at a high strain rate of 103 s-1. The proposed model is first calibrated employing a three-dimensional representative volume element model. The calibrated parameters are then employed to investigate the process of onset of strain localization in the studied material. A suitable mesh size is chosen for the proposed model by implementing a mesh-sensitivity study. The influence of boundary conditions on the initiation of the strain localization is also studied. A variation of crystallographic orientation in the studied material after the deformation process is characterized, based on results for different boundary conditions. The study reveals that the boundary conditions significantly influence the formation of shear bands as well as the variation of crystallographic orientation in the studied material. Results also indicate that the onset of strain localization can affect considerably the material's behaviour. This article is part of the theme issue 'Modelling of dynamic phenomena and localization in structured media (part 2)'.
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Affiliation(s)
- Rongxin Zhou
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
| | - Ka Ho Pang
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
| | - Anuj Bisht
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
| | - Anish Roy
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
| | - Satyam Suwas
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Vadim V. Silberschmidt
- Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough LE11 3TU, UK
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44
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El-Anwar MI, Aboelfadl AK. Comparing different bar materials for mandibular implant-supported overdenture: Finite-element analysis. Indian J Dent Res 2019; 30:716-721. [PMID: 31854362 DOI: 10.4103/0970-9290.273442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Aim This study was conducted aiming to optimize the selection of bar material that can minimize stresses on mandibular bone. Subjects and Methods One finite-element model was created under ANSYS environment to evaluate the use of different materials as a bar-manufacturing material in mandibular implant-supported overdenture (OD). Model components were created on engineering computer-aided design software and then assembled under the finite-element package. A force of 200 N was unilaterally and vertically applied on the left second premolar area. Results Within these study conditions, the polyether ether ketone bar produced the lowest Von Mises stress on OD and the maximum value of deformation. Stainless steel bar produced the maximum OD total deformation. Conclusions Cortical and spongy bones are not sensitive to the bar material. Increasing bar material stiffness increases Von Mises stresses in the bar itself and reduces its total deformation, in what is called overconstrained system.
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Affiliation(s)
- Mohamed I El-Anwar
- Department of Mechanical Engineering, National Research Centre, Giza, Egypt
| | - Ahmad K Aboelfadl
- Department of Fixed Prosthodontics, Faculty of Dentistry, Ain Shams University, Cairo, Egypt; Department of Oral Technology, University of Bonn, Bonn, Germany
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45
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Morales-García NM, Burgess TD, Hill JJ, Gill PG, Rayfield EJ. The use of extruded finite-element models as a novel alternative to tomography-based models: a case study using early mammal jaws. J R Soc Interface 2019; 16:20190674. [PMID: 31822222 PMCID: PMC6936041 DOI: 10.1098/rsif.2019.0674] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Finite-element (FE) analysis has been used in palaeobiology to assess the mechanical performance of the jaw. It uses two types of models: tomography-based three-dimensional (3D) models (very accurate, not always accessible) and two-dimensional (2D) models (quick and easy to build, good for broad-scale studies, cannot obtain absolute stress and strain values). Here, we introduce extruded FE models, which provide fairly accurate mechanical performance results, while remaining low-cost, quick and easy to build. These are simplified 3D models built from lateral outlines of a relatively flat jaw and extruded to its average width. There are two types: extruded (flat mediolaterally) and enhanced extruded (accounts for width differences in the ascending ramus). Here, we compare mechanical performance values resulting from four types of FE models (i.e. tomography-based 3D, extruded, enhanced extruded and 2D) in Morganucodon and Kuehneotherium. In terms of absolute values, both types of extruded model perform well in comparison to the tomography-based 3D models, but enhanced extruded models perform better. In terms of overall patterns, all models produce similar results. Extruded FE models constitute a viable alternative to the use of tomography-based 3D models, particularly in relatively flat bones.
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Affiliation(s)
| | - Thomas D Burgess
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK
| | - Jennifer J Hill
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK.,Smithsonian Institution, National Museum of Natural History, Washington, DC 20013-7012, USA
| | - Pamela G Gill
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK.,Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK
| | - Emily J Rayfield
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Queens Road, Bristol BS8 1RJ, UK
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46
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Wang R, Xie X, Xu X, Chen X, Xiao L. Comparison of Measurements with Finite-Element Analysis of Silicon-Diaphragm-Based Fiber-Optic Fabry-Perot Temperature Sensors. Sensors (Basel) 2019; 19:s19214780. [PMID: 31684134 PMCID: PMC6864838 DOI: 10.3390/s19214780] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/24/2019] [Accepted: 10/31/2019] [Indexed: 11/16/2022]
Abstract
Silicon-diaphragm-based fiber-optic Fabry–Perot sensors with different intracavity pressures were fabricated by anodic bonding and microelectromechanical techniques. The thermal stress and thermal expansion of the Fabry–Perot (FP) sensor caused by high-temperature bonding and temperature change were simulated by finite-element analysis. The calculated thermal stress is largest in the center and edge regions of the resonance cavity, reaching from 2 to 6 MPa. The reflection spectra and temperature sensitivity of the sensors were simulated by using a two-dimensional wave-optic model in Comsol. Theoretical calculations were also made for the FP cavity without considering silicon-diaphragm deformation and thermal stress. Four sensors with intracavity pressures of 0.01, 0.03, 0.04, and 0.05 MPa were tested at low temperatures, showing a high degree of consistency with the simulation results rather than theoretical calculation, especially for high intracavity pressure. This method is expected to aid the analysis of thermal stress generated during the bonding process and to facilitate better design and control of the temperature sensitivity of the sensor.
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Affiliation(s)
- Rongkun Wang
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Xuejian Xie
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Xiangang Xu
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Xiufang Chen
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
| | - Longfei Xiao
- State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
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47
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Klinkhamer AJ, Woodley N, Neenan JM, Parr WCH, Clausen P, Sánchez-Villagra MR, Sansalone G, Lister AM, Wroe S. Head to head: the case for fighting behaviour in Megaloceros giganteus using finite-element analysis. Proc Biol Sci 2019; 286:20191873. [PMID: 31594504 DOI: 10.1098/rspb.2019.1873] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The largest antlers of any known deer species belonged to the extinct giant deer Megaloceros giganteus. It has been argued that their antlers were too large for use in fighting, instead being used only in ritualized displays to attract mates. Here, we used finite-element analysis to test whether the antlers of M. giganteus could have withstood forces generated during fighting. We compared the mechanical performance of antlers in M. giganteus with three extant deer species: red deer (Cervus elaphus), fallow deer (Dama dama) and elk (Alces alces). Von Mises stress results suggest that M. giganteus was capable of withstanding some fighting loads, provided that their antlers interlocked proximally, and that their antlers were best adapted for withstanding loads from twisting rather than pushing actions, as are other deer with palmate antlers. We conclude that fighting in M. giganteus was probably more constrained and predictable than in extant deer.
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Affiliation(s)
- Ada J Klinkhamer
- Function, Evolution and Anatomy Research Laboratory, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - Nicholas Woodley
- School of Engineering, University of Newcastle, Callaghan, NSW 2308, Australia
| | - James M Neenan
- Oxford University Museum of Natural History, Parks Road, Oxford OX1 3PW, UK
| | - William C H Parr
- Surgical and Orthopaedic Research Laboratories, School of Clinical Sciences, Faculty of Medicine, University of New South Wales, Randwick, NSW 2031, Australia
| | - Philip Clausen
- School of Engineering, University of Newcastle, Callaghan, NSW 2308, Australia
| | - Marcelo R Sánchez-Villagra
- Paleontological Institute and Museum, University of Zurich, Karl Schmid Strasse 4, 8006 Zurich, Switzerland
| | - Gabriele Sansalone
- Function, Evolution and Anatomy Research Laboratory, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - Adrian M Lister
- Department of Earth Sciences, Natural History Museum, London SW7 5BD, UK
| | - Stephen Wroe
- Function, Evolution and Anatomy Research Laboratory, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
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48
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Albiol L, Cilla M, Pflanz D, Kramer I, Kneissel M, Duda GN, Willie BM, Checa S. Sost deficiency leads to reduced mechanical strains at the tibia midshaft in strain-matched in vivo loading experiments in mice. J R Soc Interface 2019; 15:rsif.2018.0012. [PMID: 29669893 DOI: 10.1098/rsif.2018.0012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Accepted: 03/22/2018] [Indexed: 12/18/2022] Open
Abstract
Sclerostin, a product of the Sost gene, is a Wnt-inhibitor and thus negatively regulates bone accrual. Canonical Wnt/β-catenin signalling is also known to be activated in mechanotransduction. Sclerostin neutralizing antibodies are being tested in ongoing clinical trials to target osteoporosis and osteogenesis imperfecta but their interaction with mechanical stimuli on bone formation remains unclear. Sost knockout (KO) mice were examined to gain insight into how long-term Sost deficiency alters the local mechanical environment within the bone. This knowledge is crucial as the strain environment regulates bone adaptation. We characterized the bone geometry at the tibial midshaft of young and adult Sost KO and age-matched littermate control (LC) mice using microcomputed tomography imaging. The cortical area and the minimal and maximal moment of inertia were higher in Sost KO than in LC mice, whereas no difference was detected in either the anterior-posterior or medio-lateral bone curvature. Differences observed between age-matched genotypes were greater in adult mice. We analysed the local mechanical environment in the bone using finite-element models (FEMs), which showed that strains in the tibiae of Sost KO mice are lower than in age-matched LC mice at the diaphyseal midshaft, a region commonly used to assess cortical bone formation and resorption. Our FEMs also suggested that tissue mineral density is only a minor contributor to the strain distribution in tibial cortical bone from Sost KO mice compared to bone geometry. Furthermore, they indicated that although strain gauging experiments matched strains at the gauge site, strains along the tibial length were not comparable between age-matched Sost KO and LC mice or between young and adult animals within the same genotype.
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Affiliation(s)
- Laia Albiol
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Brandenburg School for Regenerative Therapies, Berlin, Germany
| | - Myriam Cilla
- Centro Universitario de la Defensa, Academia General Militar, Zaragoza, Spain.,Aragon Institute of Engineering Research (I3A), University of Zaragoza, Zaragoza, Spain
| | - David Pflanz
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Ina Kramer
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | | | - Georg N Duda
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Brandenburg School for Regenerative Therapies, Berlin, Germany
| | - Bettina M Willie
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany.,Research Centre, Shriners Hospital for Children-Canada, Department of Pediatric Surgery, McGill University, Montreal, Canada
| | - Sara Checa
- Julius Wolff Institute, Charité-Universitätsmedizin Berlin, Berlin, Germany
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49
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Grun TB, von Scheven M, Bischoff M, Nebelsick JH. Structural stress response of segmented natural shells: a numerical case study on the clypeasteroid echinoid Echinocyamus pusillus. J R Soc Interface 2019; 15:rsif.2018.0164. [PMID: 29899160 PMCID: PMC6030617 DOI: 10.1098/rsif.2018.0164] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/16/2018] [Indexed: 11/24/2022] Open
Abstract
The skeleton of Echinocyamus pusillus is considered as an exceptional model organism for structural strength and skeletal integrity within the echinoids as demonstrated by the absence of supportive collagenous fibres between single plates and the high preservation potential of their skeletons. The structural principles behind this remarkably stable, multi-plated, light-weight construction remain hardly explored. In this study, high-resolution X-ray micro-computed tomography, finite-element analysis and physical crushing tests are used to examine the structural mechanisms of this echinoid's skeleton. The virtual model of E. pusillus shows that the material is heterogeneously distributed with high material accumulations in the internal buttress system and at the plate boundaries. Finite-element analysis indicates that the heterogeneous material distribution has no effect on the skeleton's strength. This numerical approach also demonstrates that the internal buttress system is of high significance for the overall skeletal stability of this flattened echinoid. Results of the finite-element analyses with respect to the buttress importance were evaluated by physical crushing tests. These uniaxial compression experiments support the results of the simulation analysis. Additionally, the crushing tests demonstrate that organic tissues do not significantly contribute to the skeletal stability. The strength of the echinoid shell, hence, predominantly relies on the structural design.
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Affiliation(s)
- Tobias B Grun
- Department of Geosciences, University of Tübingen, Hölderlinstraße 12, 72074 Tübingen, Germany
| | - Malte von Scheven
- Institute for Structural Mechanics, University of Stuttgart, Pfaffenwaldring 7, 70569 Stuttgart, Germany
| | - Manfred Bischoff
- Institute for Structural Mechanics, University of Stuttgart, Pfaffenwaldring 7, 70569 Stuttgart, Germany
| | - James H Nebelsick
- Department of Geosciences, University of Tübingen, Hölderlinstraße 12, 72074 Tübingen, Germany
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50
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Liang L, Liu M, Martin C, Sun W. A deep learning approach to estimate stress distribution: a fast and accurate surrogate of finite-element analysis. J R Soc Interface 2019; 15:rsif.2017.0844. [PMID: 29367242 DOI: 10.1098/rsif.2017.0844] [Citation(s) in RCA: 165] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/02/2018] [Indexed: 01/23/2023] Open
Abstract
Structural finite-element analysis (FEA) has been widely used to study the biomechanics of human tissues and organs, as well as tissue-medical device interactions, and treatment strategies. However, patient-specific FEA models usually require complex procedures to set up and long computing times to obtain final simulation results, preventing prompt feedback to clinicians in time-sensitive clinical applications. In this study, by using machine learning techniques, we developed a deep learning (DL) model to directly estimate the stress distributions of the aorta. The DL model was designed and trained to take the input of FEA and directly output the aortic wall stress distributions, bypassing the FEA calculation process. The trained DL model is capable of predicting the stress distributions with average errors of 0.492% and 0.891% in the Von Mises stress distribution and peak Von Mises stress, respectively. This study marks, to our knowledge, the first study that demonstrates the feasibility and great potential of using the DL technique as a fast and accurate surrogate of FEA for stress analysis.
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Affiliation(s)
- Liang Liang
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Technology Enterprise Park, Room 206, 387 Technology Circle, Atlanta, GA 30313-2412, USA
| | - Minliang Liu
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Technology Enterprise Park, Room 206, 387 Technology Circle, Atlanta, GA 30313-2412, USA
| | - Caitlin Martin
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Technology Enterprise Park, Room 206, 387 Technology Circle, Atlanta, GA 30313-2412, USA
| | - Wei Sun
- Tissue Mechanics Laboratory, The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Technology Enterprise Park, Room 206, 387 Technology Circle, Atlanta, GA 30313-2412, USA
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