1
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Kamani KM, Rogers SA. Brittle and ductile yielding in soft materials. Proc Natl Acad Sci U S A 2024; 121:e2401409121. [PMID: 38776367 PMCID: PMC11145261 DOI: 10.1073/pnas.2401409121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2024] [Accepted: 04/29/2024] [Indexed: 05/25/2024] Open
Abstract
Many soft materials yield under mechanical loading, but how this transition from solid-like behavior to liquid-like behavior occurs can vary significantly. Understanding the physics of yielding is of great interest for the behavior of biological, environmental, and industrial materials, including those used as inks in additive manufacturing and muds and soils. For some materials, the yielding transition is gradual, while others yield abruptly. We refer to these behaviors as being ductile and brittle. The key rheological signatures of brittle yielding include a stress overshoot in steady-shear-startup tests and a steep increase in the loss modulus during oscillatory amplitude sweeps. In this work, we show how this spectrum of yielding behaviors may be accounted for in a continuum model for yield stress materials by introducing a parameter we call the brittility factor. Physically, an increased brittility decreases the contribution of recoverable deformation to plastic deformation, which impacts the rate at which yielding occurs. The model predictions are successfully compared to results of different rheological protocols from a number of real yield stress fluids with different microstructures, indicating the general applicability of the phenomenon of brittility. Our study shows that the brittility of soft materials plays a critical role in determining the rate of the yielding transition and provides a simple tool for understanding its effects under various loading conditions.
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Affiliation(s)
- Krutarth M. Kamani
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Champaign, IL61801
| | - Simon A. Rogers
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Champaign, IL61801
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2
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Shekh Alshabab S, Markert B, Bamer F. Criticality in the fracture of silica glass: Insights from molecular mechanics. Phys Rev E 2024; 109:034110. [PMID: 38632794 DOI: 10.1103/physreve.109.034110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 02/02/2024] [Indexed: 04/19/2024]
Abstract
The universality of avalanches characterizing the inelastic response of disordered materials has the potential to bridge the gap from micro to macroscale. In this study, we explore the statistics and the scaling behavior of avalanches occurring during the fracture process in silica glass using molecular mechanics. We introduce a robust method for capturing and quantifying these avalanches, allowing us to perform rigorous statistical analyses, revealing universal power laws associated with critical phenomena. The influence of an initial crack is explored, observing deviations from mean-field predictions while maintaining the property of criticality. However, the avalanche exponents in the unnotched samples are predicted correctly by the mean-field depinning model. Furthermore, we investigate the strain-dependent probability density function, its cutoff function, and the interrelation between the critical exponents. Finally, we unveil distinct scaling behavior for small and large avalanches of the crack growth, shedding light on the underlying fracture mechanisms in silica glass.
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Affiliation(s)
| | - Bernd Markert
- Institute of General Mechanics, RWTH Aachen University, 52062 Aachen, Germany
| | - Franz Bamer
- Institute of General Mechanics, RWTH Aachen University, 52062 Aachen, Germany
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3
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Calcina-Nogales M, Atenas B, Flores JC. Griffith theory of physical fractures, statistical procedures and entropy production: Rosetta stone's legacy. PLoS One 2023; 18:e0292486. [PMID: 37922292 PMCID: PMC10624320 DOI: 10.1371/journal.pone.0292486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 09/21/2023] [Indexed: 11/05/2023] Open
Abstract
A physical model, based on energy balances, is proposed to describe the fractures in solid structures such as stelae, tiles, glass, and others. We applied the model to investigate the transition of the Rosetta Stone from the original state to the final state with three major fractures. We consider a statistical corner-breaking model with cutting rules. We obtain a probability distribution as a function of the area and the number of vertices. Our generic results are consistent with the current state of the Rosetta Stone and, additionally, predictions related to a fourth fracture are declared. The loss of information on such heritage pieces is considered through entropy production. The explicit quantification of this concept in information theory stays examined.
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Affiliation(s)
- Marcelo Calcina-Nogales
- Carrera de Física, Facultad de Ciencias Puras y Naturales, Universidad Mayor de San Andrés, La Paz, Bolivia
| | - Boris Atenas
- Departamento de Física, Facultad de Ciencias, Universidad de Tarapacá, Arica, Chile
| | - Juan Cesar Flores
- Departamento de Física, Facultad de Ciencias, Universidad de Tarapacá, Arica, Chile
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4
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Das S, Lubomirsky Y, Bouchbinder E. Dynamics of crack front waves in three-dimensional material failure. Phys Rev E 2023; 108:L043002. [PMID: 37978613 DOI: 10.1103/physreve.108.l043002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 09/18/2023] [Indexed: 11/19/2023]
Abstract
Crack front waves (FWs) are dynamic objects that propagate along moving crack fronts in three-dimensional (3D) materials. We study FW dynamics in the framework of a 3D phase-field platform that features a rate-dependent fracture energy Γ(v) (v is the crack propagation velocity) and intrinsic length scales, and quantitatively reproduces the high-speed oscillatory instability in the quasi-2D limit. We show that in-plane FWs feature a rather weak time dependence, with decay rate that increases with dΓ(v)/dv>0, and largely retain their properties upon FW-FW interactions, similarly to a related experimentally observed solitonic behavior. Driving in-plane FWs into the nonlinear regime, we find that they propagate slower than predicted by a linear perturbation theory. Finally, by introducing small out-of-plane symmetry-breaking perturbations, coupled in- and out-of-plane FWs are excited, but the out-of-plane component decays under pure tensile loading. Yet, including a small antiplane loading component gives rise to persistent coupled in- and out-of-plane FWs.
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Affiliation(s)
- Sanhita Das
- Chemical and Biological Physics Department, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Yuri Lubomirsky
- Chemical and Biological Physics Department, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Eran Bouchbinder
- Chemical and Biological Physics Department, Weizmann Institute of Science, Rehovot 7610001, Israel
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5
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Dattani UA, Karmakar S, Chaudhuri P. Universal mechanical instabilities in the energy landscape of amorphous solids: Evidence from athermal quasistatic expansion. Phys Rev E 2022; 106:055004. [PMID: 36559417 DOI: 10.1103/physreve.106.055004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 11/02/2022] [Indexed: 11/30/2022]
Abstract
Using numerical simulations, we study the failure of an amorphous solid under athermal quasistatic expansion starting from a homogeneous high-density state. During the expansion process, plastic instabilities occur, manifested via sudden jumps in pressure and energy, with the largest event happening via cavitation leading to the material's yielding. We demonstrate that all these plastic events are characterized by saddle-node bifurcation, during which the smallest nonzero eigenvalue of the Hessian matrix vanishes via a square-root singularity. We find that after yielding and prior to complete fracture, the statistics of pressure or energy jumps corresponding to the plastic events show subextensive system-size scaling, similar to the case of simple shear but with different exponents. Thus, overall, our paper reveals universal features in the fundamental characteristics during mechanical failure in amorphous solids under any quasistatic deformation protocol.
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Affiliation(s)
- Umang A Dattani
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
| | - Smarajit Karmakar
- Tata Institute of Fundamental Research, 36/P, Gopanpally Village, Serilingampally Mandal,Ranga Reddy District, Hyderabad, 500107 Telangana, India
| | - Pinaki Chaudhuri
- The Institute of Mathematical Sciences, CIT Campus, Taramani, Chennai 600113, India.,Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India
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6
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Kirchner KA, Cassar DR, Zanotto ED, Ono M, Kim SH, Doss K, Bødker ML, Smedskjaer MM, Kohara S, Tang L, Bauchy M, Wilkinson CJ, Yang Y, Welch RS, Mancini M, Mauro JC. Beyond the Average: Spatial and Temporal Fluctuations in Oxide Glass-Forming Systems. Chem Rev 2022; 123:1774-1840. [PMID: 35511603 DOI: 10.1021/acs.chemrev.1c00974] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Atomic structure dictates the performance of all materials systems; the characteristic of disordered materials is the significance of spatial and temporal fluctuations on composition-structure-property-performance relationships. Glass has a disordered atomic arrangement, which induces localized distributions in physical properties that are conventionally defined by average values. Quantifying these statistical distributions (including variances, fluctuations, and heterogeneities) is necessary to describe the complexity of glass-forming systems. Only recently have rigorous theories been developed to predict heterogeneities to manipulate and optimize glass properties. This article provides a comprehensive review of experimental, computational, and theoretical approaches to characterize and demonstrate the effects of short-, medium-, and long-range statistical fluctuations on physical properties (e.g., thermodynamic, kinetic, mechanical, and optical) and processes (e.g., relaxation, crystallization, and phase separation), focusing primarily on commercially relevant oxide glasses. Rigorous investigations of fluctuations enable researchers to improve the fundamental understanding of the chemistry and physics governing glass-forming systems and optimize structure-property-performance relationships for next-generation technological applications of glass, including damage-resistant electronic displays, safer pharmaceutical vials to store and transport vaccines, and lower-attenuation fiber optics. We invite the reader to join us in exploring what can be discovered by going beyond the average.
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Affiliation(s)
- Katelyn A Kirchner
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Daniel R Cassar
- Department of Materials Engineering, Federal University of São Carlos, São Carlos, Sao Paulo 13565-905, Brazil
- Ilum School of Science, Brazilian Center for Research in Energy and Materials, Campinas, Sao Paulo 13083-970, Brazil
| | - Edgar D Zanotto
- Department of Materials Engineering, Federal University of São Carlos, São Carlos, Sao Paulo 13565-905, Brazil
| | - Madoka Ono
- Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido 001-0021, Japan
- Materials Integration Laboratories, AGC Incorporated, Yokohama, Kanagawa 230-0045, Japan
| | - Seong H Kim
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Karan Doss
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Mikkel L Bødker
- Department of Chemistry and Bioscience, Aalborg University, Aalborg 9220, Denmark
| | - Morten M Smedskjaer
- Department of Chemistry and Bioscience, Aalborg University, Aalborg 9220, Denmark
| | - Shinji Kohara
- Research Center for Advanced Measurement and Characterization National Institute for Materials Science, 1-2-1, Sengen, Tsukuba, Ibaraki 305-0047, Japan
| | - Longwen Tang
- Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, United States
| | - Mathieu Bauchy
- Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, United States
| | - Collin J Wilkinson
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
- Department of Research and Development, GlassWRX, Beaufort, South Carolina 29906, United States
| | - Yongjian Yang
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Rebecca S Welch
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Matthew Mancini
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - John C Mauro
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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7
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Lee T, Sun Q, Beresna M, Brambilla G. Low bend loss femtosecond laser written waveguides exploiting integrated microcrack. Sci Rep 2021; 11:23770. [PMID: 34887457 PMCID: PMC8660921 DOI: 10.1038/s41598-021-03116-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 11/26/2021] [Indexed: 11/09/2022] Open
Abstract
We introduce the fabrication and use of microcracks embedded in glass as an optical element for manipulating light propagation, in particular for enhancing waveguide performance in silica integrated optics. By using a femtosecond laser to induce a strong asymmetric stress pattern in silica, uniform cracks with set dimensions can be created within the substrate and propagated along a fixed path. The smoothness of the resulting cleave interface and large index contrast can be exploited to enhance waveguide modal confinement. As a demonstration, we tackle the longstanding high bend-loss issue in femtosecond laser written silica waveguides by using this technique to cleave the outer edge of laser written waveguide bends, to suppress radiative bend loss. The microcrack cross section is estimated to be 15 μm in height and 30 nm in width, for the 10 \documentclass[12pt]{minimal}
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\begin{document}$$\times$$\end{document}× 10 μm waveguides. At 1550 nm wavelength, losses down to 1 dB/cm at 10 mm bend radius were achieved, without introducing additional scattering. Both the cleave stress pattern and waveguide are fabricated with the same multiscan writing procedure, without requiring additional steps, and re-characterisation of the waveguides after 1 year confirm excellent long term performance stability.
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Affiliation(s)
- Timothy Lee
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK.
| | - Qi Sun
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Martynas Beresna
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK
| | - Gilberto Brambilla
- Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ, UK
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8
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Shen LQ, Yu JH, Tang XC, Sun BA, Liu YH, Bai HY, Wang WH. Observation of cavitation governing fracture in glasses. SCIENCE ADVANCES 2021; 7:7/14/eabf7293. [PMID: 33789905 PMCID: PMC8011974 DOI: 10.1126/sciadv.abf7293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 02/10/2021] [Indexed: 06/12/2023]
Abstract
Crack propagation is the major vehicle for material failure, but the mechanisms by which cracks propagate remain longstanding riddles, especially for glassy materials with a long-range disordered atomic structure. Recently, cavitation was proposed as an underlying mechanism governing the fracture of glasses, but experimental determination of the cavitation behavior of fracture is still lacking. Here, we present unambiguous experimental evidence to firmly establish the cavitation mechanism in the fracture of glasses. We show that crack propagation in various glasses is dominated by the self-organized nucleation, growth, and coalescence of nanocavities, eventually resulting in the nanopatterns on the fracture surfaces. The revealed cavitation-induced nanostructured fracture morphologies thus confirm the presence of nanoscale ductility in the fracture of nominally brittle glasses, which has been debated for decades. Our observations would aid a fundamental understanding of the failure of disordered systems and have implications for designing tougher glasses with excellent ductility.
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Affiliation(s)
- Lai-Quan Shen
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ji-Hao Yu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-Chang Tang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bao-An Sun
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
| | - Yan-Hui Liu
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hai-Yang Bai
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Wei-Hua Wang
- Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
- Songshan Lake Materials Laboratory, Dongguan, Guangdong 523808, China
- College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China
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9
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Sahu P, Ali SM, Shenoy KT, Mohan S, Arvind A, Sugilal G, Kaushik CP. Molecular dynamics simulations of simplified sodium borosilicate glasses: the effect of composition on structure and dynamics. Phys Chem Chem Phys 2021; 23:14898-14912. [PMID: 34223588 DOI: 10.1039/d1cp00207d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fusion of valuable material properties has led to the acceptance of sodium borosilicate (NBS) glasses for nuclear waste immobilization. Although popular, the mechanisms associated with these properties are still only partially discovered and need further exploration. Bearing this in mind, the combination of experiments, molecular dynamics (MD) simulations and the Dell, Yuan and Bray model have been used to understand the role of composition variation for structural and physical aspects of vitrified borosilicate glasses. Experiments have been conducted to evaluate the macroscopic glass parameters of density (ρ), glass transition temperature (Tg) and thermal expansion coefficient (TEC). Experimentally observed trends for ρ, Tg and TEC with composition have been found in good agreement with the MD results. MD studies also provide a microscopic understanding of the glass structure and phenomena associated with the change in the glass composition. A detailed view of local structure and medium-range connectivity for the borosilicate glasses has been explored. Owing to a large B4 population, the results showed the abundant presence of BO4-BO4 connections, we hereby omit the generally accepted "B[4] avoidance rule" for glass. The relative propensity for connecting SiO4/BO3/BO4 structural motifs is in line with the predictions made by the Dell, Yuan and Bray model. Furthermore, the effects of composition on the mechanical integrity of NBS glasses, including the elastic nature, plastic distortion, yielding, breaking stress, and brittle fracture, have been explored by MD simulations. In addition, the glass dynamics have been evaluated by diffusion coefficient and the results suggest that Na+ is likely to be more mobile in the case of NBS1 as compared to NBS2 and NBS3 due to significant disruption in the glass network introduced by a larger amount of Na2O network modifier. Also, the diffusivity was reduced with increasing B2O3 due to the altered role of Na+ ions from network modifiers to charge compensators. The combined study of experiments, MD simulations and the Dell, Yuan and Bray model establish the correlation between the microscopic structure and macroscopic properties of NBS glasses with varied composition, which might be of great scientific use for future glasses in various applications including nuclear waste immobilization.
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Affiliation(s)
- Pooja Sahu
- Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India. and Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Sk Musharaf Ali
- Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India. and Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - K T Shenoy
- Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.
| | - Sadhana Mohan
- Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.
| | - A Arvind
- Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
| | - G Sugilal
- Homi Bhabha National Institute, Mumbai, Maharashtra, India and Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
| | - C P Kaushik
- Homi Bhabha National Institute, Mumbai, Maharashtra, India and Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
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10
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Sun K, Chen J, Wu B, Wang L, Fang L. Size-Dependent Mechanical Properties of Amorphous SiO 2 Nanowires: A Molecular Dynamics Study. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E5110. [PMID: 33198310 PMCID: PMC7696835 DOI: 10.3390/ma13225110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 06/11/2023]
Abstract
Uniaxial tension tests were performed for amorphous SiO2 nanowires using molecular dynamics simulation to probe the size effect on the mechanical properties and plastic deformation by varying the length of nanowires. The simulation results showed that the Young's modulus of SiO2 nanowires increased with the decrease of nanowires length due to its higher surface stress. The corresponding deformation of SiO2 nanowires during tension exhibited two periods: atomic arrangement at small strain and plastic deformation at large strain. During the atomic arrangement period, the percentage variations of atom number of 2-coordinated silicon and 3-coordinated silicon (PCN2 and PCN3) decreased, while the percentage variations of atom number of 4-coordinated silicon, 5-coordinated silicon (PCN4 and PCN5) and the Si-O bond number (PCB) rose slightly with increasing strain, as the strain was less than 22%. The situation reversed at the plastic deformation period, owing to the numerous breakage of Si-O bonds as the strain grew beyond 22%. The size effect of nanowires radius was considered, finding that the Young's modulus and fracture stress were higher for the larger nanowire because of fewer dangling bonds and coordinate defeats in the surface area. The elastic deformation occurred at a small strain for the larger nanowire, followed by the massive plastic deformation during tension. A brittle mechanism covers the fracture characteristics, irrespective of the nanowire size.
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Affiliation(s)
- Kun Sun
- State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China
| | - Juan Chen
- School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China;
| | - Bingjie Wu
- Nuclear Power Institute of China, Chengdu 610014, China; (B.W.); (L.W.)
| | - Liubing Wang
- Nuclear Power Institute of China, Chengdu 610014, China; (B.W.); (L.W.)
| | - Liang Fang
- State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China
- School of Mechanical & Electrical Engineering, Xiamen University Tan Kah Kee College, Zhangzhou 363105, China
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11
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Berman N, Cohen G, Fineberg J. Dynamics and Properties of the Cohesive Zone in Rapid Fracture and Friction. PHYSICAL REVIEW LETTERS 2020; 125:125503. [PMID: 33016754 DOI: 10.1103/physrevlett.125.125503] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 06/28/2020] [Accepted: 08/12/2020] [Indexed: 06/11/2023]
Abstract
The cohesive zone is the elusive region in which material fracture takes place. Here, the putatively singular stresses at a crack's tip are regularized. We present experiments, performed on PMMA, in which we visualize the cohesive zone of frictional ruptures as they propagate. Identical to shear cracks, these ruptures range from slow velocities to nearly the limiting speeds of cracks. We reveal that the cohesive zone is a dynamic quantity; its spatial form undergoes a sharp transition between distinct phases at a critical velocity. The structure of these phases provides an important window into material properties under the extreme conditions that occur during fracture.
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Affiliation(s)
- Neri Berman
- The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Gil Cohen
- The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Jay Fineberg
- The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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12
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To T, Sørensen SS, Stepniewska M, Qiao A, Jensen LR, Bauchy M, Yue Y, Smedskjaer MM. Fracture toughness of a metal-organic framework glass. Nat Commun 2020; 11:2593. [PMID: 32444664 PMCID: PMC7244719 DOI: 10.1038/s41467-020-16382-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/30/2020] [Indexed: 11/20/2022] Open
Abstract
Metal-organic framework glasses feature unique thermal, structural, and chemical properties compared to traditional metallic, organic, and oxide glasses. So far, there is a lack of knowledge of their mechanical properties, especially toughness and strength, owing to the challenge in preparing large bulk glass samples for mechanical testing. However, a recently developed melting method enables fabrication of large bulk glass samples (>25 mm3) from zeolitic imidazolate frameworks. Here, fracture toughness (KIc) of a representative glass, namely ZIF-62 glass (Zn(C3H3N2)1.75(C7H5N2)0.25), is measured using single-edge precracked beam method and simulated using reactive molecular dynamics. KIc is determined to be ~0.1 MPa m0.5, which is even lower than that of brittle oxide glasses due to the preferential breakage of the weak coordinative bonds (Zn-N). The glass is found to exhibit an anomalous brittle-to-ductile transition behavior, considering its low fracture surface energy despite similar Poisson’s ratio to that of many ductile metallic and organic glasses. Metal-organic framework glasses are gaining interest, but large samples are difficult to fabricate and mechanical properties are not well understood. Here, the authors use experiments and simulations to assess fracture toughness and flexural strength of a zeolitic imidazolate framework glass.
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Affiliation(s)
- Theany To
- Department of Chemistry and Bioscience, Aalborg University, DK-9220, Aalborg, Denmark
| | - Søren S Sørensen
- Department of Chemistry and Bioscience, Aalborg University, DK-9220, Aalborg, Denmark
| | - Malwina Stepniewska
- Department of Chemistry and Bioscience, Aalborg University, DK-9220, Aalborg, Denmark
| | - Ang Qiao
- Department of Chemistry and Bioscience, Aalborg University, DK-9220, Aalborg, Denmark
| | - Lars R Jensen
- Department of Materials and Production, Aalborg University, DK-9220, Aalborg, Denmark
| | - Mathieu Bauchy
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Yuanzheng Yue
- Department of Chemistry and Bioscience, Aalborg University, DK-9220, Aalborg, Denmark
| | - Morten M Smedskjaer
- Department of Chemistry and Bioscience, Aalborg University, DK-9220, Aalborg, Denmark.
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13
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Frankberg EJ, Kalikka J, García Ferré F, Joly-Pottuz L, Salminen T, Hintikka J, Hokka M, Koneti S, Douillard T, Le Saint B, Kreiml P, Cordill MJ, Epicier T, Stauffer D, Vanazzi M, Roiban L, Akola J, Di Fonzo F, Levänen E, Masenelli-Varlot K. Highly ductile amorphous oxide at room temperature and high strain rate. Science 2019; 366:864-869. [DOI: 10.1126/science.aav1254] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 07/03/2019] [Accepted: 10/08/2019] [Indexed: 11/02/2022]
Affiliation(s)
- Erkka J. Frankberg
- Unit of Materials Science and Environmental Engineering, Tampere University, Tampere, Finland
- Université de Lyon, INSA-Lyon, UCBL, MATEIS, CNRS UMR 5510, Villeurbanne, France
- Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, Milano, Italy
| | - Janne Kalikka
- Computational Physics Laboratory, Tampere University, Tampere, Finland
| | - Francisco García Ferré
- Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, Milano, Italy
| | - Lucile Joly-Pottuz
- Université de Lyon, INSA-Lyon, UCBL, MATEIS, CNRS UMR 5510, Villeurbanne, France
| | - Turkka Salminen
- Tampere Microscopy Center, Tampere University, Tampere, Finland
| | - Jouko Hintikka
- Unit of Materials Science and Environmental Engineering, Tampere University, Tampere, Finland
| | - Mikko Hokka
- Unit of Materials Science and Environmental Engineering, Tampere University, Tampere, Finland
| | - Siddardha Koneti
- Université de Lyon, INSA-Lyon, UCBL, MATEIS, CNRS UMR 5510, Villeurbanne, France
| | - Thierry Douillard
- Université de Lyon, INSA-Lyon, UCBL, MATEIS, CNRS UMR 5510, Villeurbanne, France
| | - Bérangère Le Saint
- Université de Lyon, INSA-Lyon, UCBL, MATEIS, CNRS UMR 5510, Villeurbanne, France
| | - Patrice Kreiml
- Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, Austria
| | - Megan J. Cordill
- Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Leoben, Austria
| | - Thierry Epicier
- Université de Lyon, INSA-Lyon, UCBL, MATEIS, CNRS UMR 5510, Villeurbanne, France
| | | | - Matteo Vanazzi
- Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, Milano, Italy
| | - Lucian Roiban
- Université de Lyon, INSA-Lyon, UCBL, MATEIS, CNRS UMR 5510, Villeurbanne, France
| | - Jaakko Akola
- Computational Physics Laboratory, Tampere University, Tampere, Finland
- Department of Physics, Norwegian University of Science and Technology, Trondheim, Norway
| | - Fabio Di Fonzo
- Center for Nano Science and Technology @PoliMi, Istituto Italiano di Tecnologia, Milano, Italy
| | - Erkki Levänen
- Unit of Materials Science and Environmental Engineering, Tampere University, Tampere, Finland
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14
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Zhang Y, Huang L, Shi Y. Silica Glass Toughened by Consolidation of Glassy Nanoparticles. NANO LETTERS 2019; 19:5222-5228. [PMID: 31295399 DOI: 10.1021/acs.nanolett.9b01634] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The brittleness of oxide glasses has dramatically restricted their practical applications as structural materials despite very high theoretical strength. Herein, using molecular dynamics simulations, we show that silica glass prepared by consolidating glassy nanoparticles exhibit remarkable tensile ductility. Because of dangling bonds at surfaces and high contact stresses, the pressure applied for consolidating glassy nanoparticles to achieve ductility is significantly lower than that required to toughen bulk glass via permanent densification. We have identified 5-fold silicon, with a higher propensity to carry out local shear deformation than 4-fold silicon, as the structural origin for the observed tensile ductility. Interestingly, the work hardening effect has been, for the first time, observed in thus-prepared silica glass, with its strength increasing from 4 GPa to ∼7 GPa upon cold work. This is due to stress-assisted relaxation of 5-fold silicon to 4-fold during cold work, analogous to transformation hardening.
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Affiliation(s)
- Yanming Zhang
- Department of Materials Science and Engineering , Rensselaer Polytechnic Institute , 110 Eighth Street , Troy , New York 12180 , United States
| | - Liping Huang
- Department of Materials Science and Engineering , Rensselaer Polytechnic Institute , 110 Eighth Street , Troy , New York 12180 , United States
| | - Yunfeng Shi
- Department of Materials Science and Engineering , Rensselaer Polytechnic Institute , 110 Eighth Street , Troy , New York 12180 , United States
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15
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Bonfanti S, Ferrero EE, Sellerio AL, Guerra R, Zapperi S. Damage Accumulation in Silica Glass Nanofibers. NANO LETTERS 2018; 18:4100-4106. [PMID: 29856226 DOI: 10.1021/acs.nanolett.8b00469] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The origin of the brittle-to-ductile transition, experimentally observed in amorphous silica nanofibers as the sample size is reduced, is still debated. Here we investigate the issue by extensive molecular dynamics simulations at low and room temperatures for a broad range of sample sizes, with open and periodic boundary conditions. Our results show that small sample-size enhanced ductility is primarily due to diffuse damage accumulation, that for larger samples leads to brittle catastrophic failure. Surface effects such as boundary fluidization contribute to ductility at room temperature by promoting necking, but are not the main driver of the transition. Our results suggest that the experimentally observed size-induced ductility of silica nanofibers is a manifestation of finite-size criticality, as expected in general for quasi-brittle disordered networks.
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Affiliation(s)
- Silvia Bonfanti
- Center for Complexity and Biosystems, Department of Physics , University of Milano , via Celoria 16 , 20133 Milano , Italy
| | - Ezequiel E Ferrero
- Center for Complexity and Biosystems, Department of Physics , University of Milano , via Celoria 16 , 20133 Milano , Italy
- CONICET, Centro Atómico Bariloche , Av. Bustillo 9500 , 8400 S. C. de Bariloche , Río Negro Argentina
| | - Alessandro L Sellerio
- Center for Complexity and Biosystems, Department of Physics , University of Milano , via Celoria 16 , 20133 Milano , Italy
| | - Roberto Guerra
- Center for Complexity and Biosystems, Department of Physics , University of Milano , via Celoria 16 , 20133 Milano , Italy
| | - Stefano Zapperi
- Center for Complexity and Biosystems, Department of Physics , University of Milano , via Celoria 16 , 20133 Milano , Italy
- Consiglio Nazionale delle Ricerche , Istituto di Chimica della Materia Condensata e di Tecnologie per l'Energia , Via R. Cozzi 53 , 20125 Milano , Italy
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16
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Microscopic dynamics and failure precursors of a gel under mechanical load. Proc Natl Acad Sci U S A 2018; 115:3587-3592. [PMID: 29555776 DOI: 10.1073/pnas.1717403115] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Material failure is ubiquitous, with implications from geology to everyday life and material science. It often involves sudden, unpredictable events, with little or no macroscopically detectable precursors. A deeper understanding of the microscopic mechanisms eventually leading to failure is clearly required, but experiments remain scarce. Here, we show that the microscopic dynamics of a colloidal gel, a model network-forming system, exhibit dramatic changes that precede its macroscopic failure by thousands of seconds. Using an original setup coupling light scattering and rheology, we simultaneously measure the macroscopic deformation and the microscopic dynamics of the gel, while applying a constant shear stress. We show that the network failure is preceded by qualitative and quantitative changes of the dynamics, from reversible particle displacements to a burst of irreversible plastic rearrangements.
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17
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Urata S, Sato Y. A study on the plasticity of soda-lime silica glass via molecular dynamics simulations. J Chem Phys 2017; 147:174501. [DOI: 10.1063/1.4997293] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Shingo Urata
- Innovative Technology Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku Yokohama, Kanagawa 221-8755, Japan
| | - Yosuke Sato
- Innovative Technology Research Center, Asahi Glass Co., Ltd., 1150 Hazawa-cho, Kanagawa-ku Yokohama, Kanagawa 221-8755, Japan
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18
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Singh I, Narasimhan R, Ramamurty U. Cavitation-Induced Fracture Causes Nanocorrugations in Brittle Metallic Glasses. PHYSICAL REVIEW LETTERS 2016; 117:044302. [PMID: 27494475 DOI: 10.1103/physrevlett.117.044302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Indexed: 06/06/2023]
Abstract
Brittle metallic glasses exhibit a unique and intriguing fracture morphology of periodic nanocorrugations whose spacing and amplitude are of the order of tens of nanometers. We show through continuum simulations that they fail by spontaneous and simultaneous cavitation within multiple weak zones arising due to intrinsic atomic density fluctuations ahead of a notch tip. Dynamic crack growth would then occur along curved but narrowly confined shear bands that link the growing cavities. This mechanism involves little dissipation and also explains the formation of nanocorrugations.
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Affiliation(s)
- I Singh
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560012, India
| | - R Narasimhan
- Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Upadrasta Ramamurty
- Department of Materials Engineering, Indian Institute of Science, Bangalore 560012, India
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19
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Luo J, Wang J, Bitzek E, Huang JY, Zheng H, Tong L, Yang Q, Li J, Mao SX. Size-Dependent Brittle-to-Ductile Transition in Silica Glass Nanofibers. NANO LETTERS 2016; 16:105-113. [PMID: 26569137 DOI: 10.1021/acs.nanolett.5b03070] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Silica (SiO2) glass, an essential material in human civilization, possesses excellent formability near its glass-transition temperature (Tg > 1100 °C). However, bulk SiO2 glass is very brittle at room temperature. Here we show a surprising brittle-to-ductile transition of SiO2 glass nanofibers at room temperature as its diameter reduces below 18 nm, accompanied by ultrahigh fracture strength. Large tensile plastic elongation up to 18% can be achieved at low strain rate. The unexpected ductility is due to a free surface affected zone in the nanofibers, with enhanced ionic mobility compared to the bulk that improves ductility by producing more bond-switching events per irreversible bond loss under tensile stress. Our discovery is fundamentally important for understanding the damage tolerance of small-scale amorphous structures.
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Affiliation(s)
- Junhang Luo
- Department of Mechanical Engineering & Materials Science, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Jiangwei Wang
- Department of Mechanical Engineering & Materials Science, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Erik Bitzek
- Department of Nuclear Science and Engineering and Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Department of Materials Science and Engineering, Institute I, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) , 91058 Erlangen, Germany
| | | | - He Zheng
- Department of Mechanical Engineering & Materials Science, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
| | - Limin Tong
- State Key Laboratory of Modern Optical Instrumentation, Department of Optical Engineering, Zhejiang University , Hangzhou 310027, China
| | - Qing Yang
- State Key Laboratory of Modern Optical Instrumentation, Department of Optical Engineering, Zhejiang University , Hangzhou 310027, China
| | - Ju Li
- Department of Nuclear Science and Engineering and Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | - Scott X Mao
- Department of Mechanical Engineering & Materials Science, University of Pittsburgh , Pittsburgh, Pennsylvania 15261, United States
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20
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A Monolithic Micro-Tensile Tester for Investigating Silicon Dioxide Polymorph Micromechanics, Fabricated and Operated Using a Femtosecond Laser. MICROMACHINES 2015. [DOI: 10.3390/mi6091365] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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Vasseur J, Wadsworth FB, Lavallée Y, Bell AF, Main IG, Dingwell DB. Heterogeneity: The key to failure forecasting. Sci Rep 2015; 5:13259. [PMID: 26307196 PMCID: PMC4549791 DOI: 10.1038/srep13259] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 07/23/2015] [Indexed: 11/17/2022] Open
Abstract
Elastic waves are generated when brittle materials are subjected to increasing strain. Their number and energy increase non-linearly, ending in a system-sized catastrophic failure event. Accelerating rates of geophysical signals (e.g., seismicity and deformation) preceding large-scale dynamic failure can serve as proxies for damage accumulation in the Failure Forecast Method (FFM). Here we test the hypothesis that the style and mechanisms of deformation, and the accuracy of the FFM, are both tightly controlled by the degree of microstructural heterogeneity of the material under stress. We generate a suite of synthetic samples with variable heterogeneity, controlled by the gas volume fraction. We experimentally demonstrate that the accuracy of failure prediction increases drastically with the degree of material heterogeneity. These results have significant implications in a broad range of material-based disciplines for which failure forecasting is of central importance. In particular, the FFM has been used with only variable success to forecast failure scenarios both in the field (volcanic eruptions and landslides) and in the laboratory (rock and magma failure). Our results show that this variability may be explained, and the reliability and accuracy of forecast quantified significantly improved, by accounting for material heterogeneity as a first-order control on forecasting power.
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Affiliation(s)
- Jérémie Vasseur
- Earth and Environmental Sciences, Ludwig Maximilian University, Munich, Germany
| | - Fabian B Wadsworth
- Earth and Environmental Sciences, Ludwig Maximilian University, Munich, Germany
| | - Yan Lavallée
- Earth, Ocean and Ecological Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Andrew F Bell
- School of Geosciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Ian G Main
- School of Geosciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Donald B Dingwell
- Earth and Environmental Sciences, Ludwig Maximilian University, Munich, Germany
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22
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Dalbe MJ, Koivisto J, Vanel L, Miksic A, Ramos O, Alava M, Santucci S. Repulsion and Attraction between a Pair of Cracks in a Plastic Sheet. PHYSICAL REVIEW LETTERS 2015; 114:205501. [PMID: 26047240 DOI: 10.1103/physrevlett.114.205501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Indexed: 06/04/2023]
Abstract
We study the interaction of two collinear cracks in polymer sheets slowly growing towards each other, when submitted to uniaxial stress at a constant loading velocity. Depending on the sample's geometry-specifically, the initial distances d between the two cracks' axes and L between the cracks' tips-we observe different crack paths with, in particular, a regime where the cracks repel each other prior to being attracted. We show that the angle θ characterizing the amplitude of the repulsion-and specifically its evolution with d-depends strongly on the microscopic behavior of the material. Our results highlight the crucial role of the fracture process zone. At interaction distances larger than the process zone size, crack repulsion is controlled by the microscopic shape of the process zone tip, while at shorter distances, the overall plastic process zone screens the repulsion interaction.
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Affiliation(s)
- Marie-Julie Dalbe
- Laboratoire de Physique de l'Ecole Normale Supérieure de Lyon, UMR CNRS 5672, Université de Lyon, 69364 Lyon Cedex 07, France
- Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne, France
| | - Juha Koivisto
- COMP Center of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Espoo, Finland
| | - Loïc Vanel
- Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne, France
| | - Amandine Miksic
- COMP Center of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Espoo, Finland
| | - Osvanny Ramos
- Institut Lumière Matière, UMR5306 Université Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne, France
| | - Mikko Alava
- COMP Center of Excellence, Department of Applied Physics, Aalto University, 00076 Aalto, Espoo, Finland
| | - Stéphane Santucci
- Laboratoire de Physique de l'Ecole Normale Supérieure de Lyon, UMR CNRS 5672, Université de Lyon, 69364 Lyon Cedex 07, France
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23
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Brittle to ductile transition in densified silica glass. Sci Rep 2014; 4:5035. [PMID: 24849328 PMCID: PMC4030258 DOI: 10.1038/srep05035] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 05/02/2014] [Indexed: 11/30/2022] Open
Abstract
Current understanding of the brittleness of glass is limited by our poor understanding and control over the microscopic structure. In this study, we used a pressure quenching route to tune the structure of silica glass in a controllable manner, and observed a systematic increase in ductility in samples quenched under increasingly higher pressure. The brittle to ductile transition in densified silica glass can be attributed to the critical role of 5-fold Si coordination defects (bonded to 5 O neighbors) in facilitating shear deformation and in dissipating energy by converting back to the 4-fold coordination state during deformation. As an archetypal glass former and one of the most abundant minerals in the Earth's crest, a fundamental understanding of the microscopic structure underpinning the ductility of silica glass will not only pave the way toward rational design of strong glasses, but also advance our knowledge of the geological processes in the Earth's interior.
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24
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Impact of oral fluids on dental ceramics: What is the clinical relevance? Dent Mater 2014; 30:33-42. [DOI: 10.1016/j.dental.2013.08.199] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Revised: 08/05/2013] [Accepted: 08/08/2013] [Indexed: 02/04/2023]
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25
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Procaccia I, Zylberg J. Propagation mechanism of brittle cracks. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:012801. [PMID: 23410382 DOI: 10.1103/physreve.87.012801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Indexed: 06/01/2023]
Abstract
We employ a recently developed model that allows the study of two-dimensional brittle crack propagation under fixed grip boundary conditions. The crack development highlights the importance of voids which appear ahead of the crack as observed in experiments on the nanoscale. The appearance of these voids is responsible for roughening the crack path on small scales, in agreement with theoretical expectations. With increasing speed of propagation one observes the branching instabilities that were reported in experiments. The simulations allow understanding the phenomena by analyzing the elastic stress field that accompanies the crack dynamics.
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Affiliation(s)
- Itamar Procaccia
- Department of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, Israel
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26
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Tanaka Y. Reduced stress concentration and enhanced fracture toughness by yielding-rehardening combination. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2012; 35:1-8. [PMID: 22438042 DOI: 10.1140/epje/i2012-12023-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2011] [Revised: 12/30/2011] [Accepted: 02/29/2012] [Indexed: 05/31/2023]
Abstract
A range of tough materials (e.g., metals and polymer solids) exhibit a characteristic mechanical behavior, that is, a combination of yielding and subsequent rehardening. We numerically investigate how the combination of these mechanical behaviors enhances resistance to crack propagation.Our system has a 2-dimensional square lattice structure where pairs of adjacent lattice points are connected by "special" bonds. An isolated bond behaves as a linear spring for small deformations, but yields at a threshold force to produce a plateau in its force-deformation curve, and then shows rehardening on further loading up to a critical force of bond-breaking; on unloading from above the yielding point, the force rapidly decreases with deformation (hysteresis). We simulate crack propagation in the entire system (the square lattice structure) from an initial crack driven by boundary loading. The threshold force for bond-yielding is varied as a simulation parameter, while the critical force for bond-breaking in the rehardening regime is fixed to 1. In other words, the substantial simulation parameter is the ratio between the yielding and breaking forces. We find that the fracture behavior drastically changes depending on the ratio: when the ratio is low, the bond-breaking energy (of a single bond) is low, but more work is required to fracture the entire system via the crack propagation. The opposite tendency between the bond-breaking energy and the fracture work is due to formation of a well-developed yielding zone around the crack tip.
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Affiliation(s)
- Y Tanaka
- Faculty of Environmental and Information Science, Yokohama National University, Japan.
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27
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Wondraczek L, Mauro JC, Eckert J, Kühn U, Horbach J, Deubener J, Rouxel T. Towards ultrastrong glasses. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2011; 23:4578-4586. [PMID: 22103001 DOI: 10.1002/adma.201102795] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The development of new glassy materials is key for addressing major global challenges in energy, medicine, and advanced communications systems. For example, thin, flexible, and large-area glass substrates will play an enabling role in the development of flexible displays, roll-to-roll processing of solar cells, next-generation touch-screen devices, and encapsulation of organic semiconductors. The main drawback of glass and its limitation for these applications is its brittle fracture behavior, especially in the presence of surface flaws, which can significantly reduce the practical strength of a glass product. Hence, the design of new ultrastrong glassy materials and strengthening techniques is of crucial importance. The main issues regarding glass strength are discussed, with an emphasis on the underlying microscopic mechanisms that are responsible for mechanical properties. The relationship among elastic properties and fracture behavior is also addressed, focusing on both oxide and metallic glasses. From a theoretical perspective, atomistic modeling of mechanical properties of glassy materials is considered. The topological origin of these properties is also discussed, including its relation to structural and chemical heterogeneities. Finally, comments are given on several toughening strategies for increasing the damage resistance of glass products.
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Affiliation(s)
- Lothar Wondraczek
- Department of Materials Science, University of Erlangen-Nuremberg, Erlangen 91058, Germany.
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28
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Dullens RPA, Bechinger C. Shear thinning and local melting of colloidal crystals. PHYSICAL REVIEW LETTERS 2011; 107:138301. [PMID: 22026907 DOI: 10.1103/physrevlett.107.138301] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Indexed: 05/31/2023]
Abstract
Phenomena such as shear thinning and thickening, occurring when complex materials are exposed to external forces, are generally believed to be closely connected to changes in the microstructure. Here, we establish a direct and quantitative relation between shear thinning in a colloidal crystal and the surface area of the locally melted region by dragging a probe particle through the crystal using optical tweezing. We show that shear thinning originates from the nonlinear dependence of the locally melted surface area on the drag velocity. Our observations provide unprecedented quantitative evidence for the intimate relation between mechanical properties and underlying changes in microscopic structure.
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29
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Lechenault F, Rountree CL, Cousin F, Bouchaud JP, Ponson L, Bouchaud E. Evidence of deep water penetration in silica during stress corrosion fracture. PHYSICAL REVIEW LETTERS 2011; 106:165504. [PMID: 21599383 DOI: 10.1103/physrevlett.106.165504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Indexed: 05/30/2023]
Abstract
We measure the thickness of the heavy water layer trapped under the stress corrosion fracture surface of silica using neutron reflectivity experiments. We show that the penetration depth is 65-85 Å, suggesting the presence of a damaged zone of ∼100 Å extending ahead of the crack tip during its propagation. This estimate of the size of the damaged zone is compatible with other recent results.
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Affiliation(s)
- F Lechenault
- CEA-Saclay, IRAMIS, SPEC, F-91191 Gif-sur-Yvette, France
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30
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Pezzotti G, Leto A. Contribution of spatially and spectrally resolved cathodoluminescence to study crack-tip phenomena in silica glass. PHYSICAL REVIEW LETTERS 2009; 103:175501. [PMID: 19905769 DOI: 10.1103/physrevlett.103.175501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Indexed: 05/28/2023]
Abstract
A current controversy over the nature of fracture in silica glass is revisited in the light of additional experimental evidence obtained by cathodoluminescence (CL) spectroscopy in the immediate crack-tip zone of two different types of silica glass. The Letter describes the dual experimental output obtained by monitoring optically active oxygen defects in silica glass, as follows: (i) analysis of local crack-tip stoichiometry (i.e., lattice defect population); and, (ii) spatially resolved stress analysis ahead of the crack tip based on a piezo-spectroscopic (PS) approach. CL experiments provided us with direct access to crack-tip stress fields, thus unfolding some missing detail about the complex mechanochemical interactions occurring at the crack tip in silica glass.
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Affiliation(s)
- Giuseppe Pezzotti
- Ceramic Physics Laboratory & Research Institute for Nanoscience, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, 606-8585 Kyoto, Japan
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31
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Chen YC, Nomura KI, Kalia RK, Nakano A, Vashishta P. Void deformation and breakup in shearing silica glass. PHYSICAL REVIEW LETTERS 2009; 103:035501. [PMID: 19659293 DOI: 10.1103/physrevlett.103.035501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2009] [Indexed: 05/28/2023]
Abstract
We study shear deformation and breakup of voids in silica glass using molecular dynamics simulations. With an increase in the shear strain, two kinds of defects--threefold-coordinated silicon and nonbridging oxygen atoms--appear as spherical voids deform elastically into ellipsoidal shapes. For shear strains epsilon>15%, nanocracks appear on void surfaces and voids deform plastically into a threadlike structure. Nanocracks are nucleated by the migration of threefold-coordinated Si and nonbridging O on -Si-O-Si-O- rings. For epsilon>40%, the threadlike structures break up into several fragments.
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Affiliation(s)
- Yi-Chun Chen
- Department of Physics and Astronomy, Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089-0242, USA
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32
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Livne A, Bouchbinder E, Fineberg J. Breakdown of linear elastic fracture mechanics near the tip of a rapid crack. PHYSICAL REVIEW LETTERS 2008; 101:264301. [PMID: 19437643 DOI: 10.1103/physrevlett.101.264301] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We present high resolution measurements of the displacement and strain fields near the tip of a dynamic (mode I) crack. The experiments are performed on polyacrylamide gels, brittle elastomers whose fracture dynamics mirror those of typical brittle amorphous materials. Over a wide range of propagation velocities (0.2-0.8c(s)), we compare linear elastic fracture mechanics (LEFM) to the measured near-tip fields. We find that, sufficiently near the tip, the measured stress intensity factor appears to be nonunique, the crack tip significantly deviates from its predicted parabolic form, and the strains ahead of the tip are more singular than the r(-1/2) divergence predicted by LEFM. These results show how LEFM breaks down as the crack tip is approached.
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Affiliation(s)
- Ariel Livne
- Racah Institute of Physics, Hebrew University of Jerusalem, Jerusalem 91904, Israel
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33
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Dalmas D, Lelarge A, Vandembroucq D. Crack propagation through phase-separated glasses: effect of the characteristic size of disorder. PHYSICAL REVIEW LETTERS 2008; 101:255501. [PMID: 19113722 DOI: 10.1103/physrevlett.101.255501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2007] [Indexed: 05/27/2023]
Abstract
We perform fracture experiments on nanoscale phase-separated glasses and measure crack surface roughness by atomic force microscopy. The ability of tuning the phase domain size by thermal treatment allows us to test thoroughly the predictions of crack front depinning models about the scaling properties of crack surface roughness. It appears that, in the range of validity of these depinning models developed for the fracture of brittle materials, our experimental results show a quantitative agreement with theoretical predictions: Beyond the characteristic size of disorder, the roughness of crack surfaces obeys the logarithmic scaling early predicted by Ramanathan, Ertaş, and Fisher [Phys. Rev. Lett. 79, 873 (1997)].
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Affiliation(s)
- Davy Dalmas
- Unité Mixte CNRS/Saint-Gobain "Surface du Verre et Interfaces," 39 Quai Lucien Lefranc, 93303 Aubervilliers cedex, France
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34
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Chen YC, Lu Z, Nomura KI, Wang W, Kalia RK, Nakano A, Vashishta P. Interaction of voids and nanoductility in silica glass. PHYSICAL REVIEW LETTERS 2007; 99:155506. [PMID: 17995183 DOI: 10.1103/physrevlett.99.155506] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 07/27/2007] [Indexed: 05/25/2023]
Abstract
Multimillion-to-billion-atom molecular dynamics simulations are performed to investigate the interaction of voids in silica glass under hydrostatic tension. Nanometer size cavities nucleate in intervoid ligaments as a result of the expansion of Si-O rings due to a bond-switching mechanism, which involves bond breaking between Si-O and bond formation between that Si and a nonbridging O. With further increase in strain, nanocracks form on void surfaces and ligaments fracture through the growth and coalescence of ligament nanocavities in a manner similar to that observed in ductile metallic alloys.
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Affiliation(s)
- Yi-Chun Chen
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089-0242, USA
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35
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Santucci S, Måløy KJ, Delaplace A, Mathiesen J, Hansen A, Haavig Bakke JØ, Schmittbuhl J, Vanel L, Ray P. Statistics of fracture surfaces. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 75:016104. [PMID: 17358221 DOI: 10.1103/physreve.75.016104] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2006] [Revised: 10/23/2006] [Indexed: 05/14/2023]
Abstract
We analyze the statistical distribution function for the height fluctuations of brittle fracture surfaces using extensive experimental data sampled on widely different materials and geometries. We compare a direct measurement of the distribution to an analysis based on the structure functions. For length scales delta larger than a characteristic scale Lambda that corresponds to a material heterogeneity size, we find that the distribution of the height increments Deltah=h(x+delta)-h(x) is Gaussian and monoaffine, i.e., the scaling of the standard deviation sigma is proportional to delta(zeta) with a unique roughness exponent. Below the scale Lambda we observe a deviation from a Gaussian distribution and a monoaffine behavior. We discuss for the latter, the relevance of a multiaffine analysis and the influences of the discreteness resulting from material microstructures or experimental sampling.
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Affiliation(s)
- Stéphane Santucci
- Department of Physics, University of Oslo, P. O. Box 1048 Blindern, N-0316 Oslo, Norway
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36
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Bonamy D, Ponson L, Prades S, Bouchaud E, Guillot C. Scaling exponents for fracture surfaces in homogeneous glass and glassy ceramics. PHYSICAL REVIEW LETTERS 2006; 97:135504. [PMID: 17026045 DOI: 10.1103/physrevlett.97.135504] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Indexed: 05/12/2023]
Abstract
We investigate the scaling properties of postmortem fracture surfaces in silica glass and glassy ceramics. In both cases, the 2D height-height correlation function is found to obey Family-Viseck scaling properties, but with two sets of critical exponents, in particular, a roughness exponent zeta approximately 0.75 in homogeneous glass and zeta approximately 0.4 in glassy ceramics. The ranges of length scales over which these two scalings are observed are shown to be below and above the size of the process zone, respectively. A model derived from linear elastic fracture mechanics in the quasistatic approximation succeeds to reproduce the scaling exponents observed in glassy ceramics. The critical exponents observed in homogeneous glass are conjectured to reflect the damage screening occurring for length scales below the size of the process zone.
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Affiliation(s)
- D Bonamy
- Service de Physique et Chimie des Surfaces et Interfaces, DSM/DRECAM/SPCSI, CEA Saclay, F-91191 Gif sur Yvette, France
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37
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38
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Jarvis EAA, Carter EA. A nanoscale mechanism of fatigue in ionic solids. NANO LETTERS 2006; 6:505-9. [PMID: 16522052 DOI: 10.1021/nl0525655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
We employ periodic density functional theory to explore the effect of cyclic tensile loading on the behavior of alumina in the threshold region of crack formation. We find evidence for nanoscale fatigue when the alumina lattice is subjected to uniaxial tensile loading and unloading and tensile stresses normal to the applied load. It is possible that such atomic-scale fatigue impacts the durability of ceramics, since the highly ionic bonding requires near-ideal lattice structures in order to maintain cohesive strength.
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Affiliation(s)
- Emily A A Jarvis
- National Institute of Standards and Technology, 100 Bureau Drive, Stop 8380, Gaithersburg, Maryland 20899-8380, USA
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39
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Zhu T, Li J, Yip S. Atomistic characterization of three-dimensional lattice trapping barriers to brittle fracture. Proc Math Phys Eng Sci 2006. [DOI: 10.1098/rspa.2005.1567] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
We present a detailed account of an atomistic study of three-dimensional lattice trapping barriers to brittle fracture in Si. By means of a prototypical interatomic potential model, we map out the molecular details of the evolution of atomically sharp cracks in the (111) cleavage plane with straight crack fronts along the
and
directions, respectively. The thermally activated processes of bond rupturing along the crack front are quantitatively characterized using a reaction pathway sampling scheme. The calculated minimum energy paths reveal a mechanism of kink-pair formation and migration in facilitating the crack front advancement. We show that the physical origin of directional anisotropy in cleavage crack propagation can be attributed to a difference in the kink-pair formation energy for different crack orientations. The effects of interatomic potentials are delineated by comparing the Stillinger–Weber model with an environment-dependent model.
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Affiliation(s)
- Ting Zhu
- Department of Mechanical Engineering, Massachusetts Institute of TechnologyCambridge, MA 02139, USA
| | - Ju Li
- Department of Materials Science and Engineering, Ohio State UniversityColumbus, OH 43210, USA
| | - Sidney Yip
- Departments of Nuclear Science and Engineering and Materials Science and Engineering, Massachusetts Institute of TechnologyCambridge, MA 02139, USA
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40
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Måløy KJ, Santucci S, Schmittbuhl J, Toussaint R. Local waiting time fluctuations along a randomly pinned crack front. PHYSICAL REVIEW LETTERS 2006; 96:045501. [PMID: 16486839 DOI: 10.1103/physrevlett.96.045501] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Indexed: 05/06/2023]
Abstract
The propagation of an interfacial crack along a heterogeneous weak plane of a transparent Plexiglas block is followed using a high resolution fast camera. We show that the fracture front dynamics is governed by local and irregular avalanches with very large size and velocity fluctuations. We characterize the intermittent dynamics observed, i.e., the local pinnings and depinnings of the crack front by measuring the local waiting time fluctuations along the crack front during its propagation. The deduced local front line velocity distribution exhibits a power law behavior, P(v) alpha v-eta with eta=2.55+/-0.15, for velocities v larger than the average front speed <v>. The burst size distribution is also a power law, P(S) alpha S-gamma with gamma=1.7+/-0.1. Above a characteristic length scale of disorder Ld approximately 15 microm, the avalanche clusters become anisotropic providing an estimate of the roughness exponent of the crack front line, H=0.66.
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Affiliation(s)
- Knut Jørgen Måløy
- Fysisk Institutt, Universitetet i Oslo, P.O. Boks 1048 Blindern, N-0316 Oslo 3, Norway
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41
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Lu Z, Nomura KI, Sharma A, Wang W, Zhang C, Nakano A, Kalia R, Vashishta P, Bouchaud E, Rountree C. Dynamics of wing cracks and nanoscale damage in glass. PHYSICAL REVIEW LETTERS 2005; 95:135501. [PMID: 16197145 DOI: 10.1103/physrevlett.95.135501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2005] [Indexed: 05/04/2023]
Abstract
We investigate initiation, growth, and healing of wing cracks in confined silica glass by molecular dynamics simulations. Under dynamic compression, frictional sliding of precrack surfaces nucleates nanovoids which evolve into nanocrack columns at the precrack tip. Nanocrack columns merge to form a wing crack, which grows via coalescence with nanovoids in the direction of maximum compression. Lateral confinement arrests the growth and partially heals the wing crack. Growth and arrest of the wing crack occur repeatedly, as observed in dynamic compression experiments on brittle solids under lateral confinement.
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Affiliation(s)
- Zhen Lu
- Collaboratory for Advanced Computing and Simulations, University of Southern California, Los Angeles, California 90089-0242, USA
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42
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Lu C, Mai YW, Shen YG. Optimum information in crackling noise. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 72:027101. [PMID: 16196751 DOI: 10.1103/physreve.72.027101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Indexed: 05/04/2023]
Abstract
The crackling noise due to scratching superhard nanocomposite coatings was investigated by using a simple stick-slip model. The optimum information extracted from statistical analysis, in terms of the Akaike information criterion, is in good agreement with real tests. As a nanocomposite coating approaches an optimal performance, the acoustic emission energy follows a power-law distribution and its behavior is likely to be independent of microscopic and macroscopic details. The results imply that a peculiar deformation behavior, due to the competition between different deformation mechanisms such as dislocation pile-ups in nanocrystalline grains and grain sliding-grain rotation within amorphous boundaries, plays a vital role in the nanostructure with superhardness.
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Affiliation(s)
- Chunsheng Lu
- Centre for Advanced Materials Technology (CAMT), School of Aerospace, Mechanical and Mechatronic Engineering J07, The University of Sydney, Sydney, NSW 2006, Australia.
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43
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Afek I, Bouchbinder E, Katzav E, Mathiesen J, Procaccia I. Void formation and roughening in slow fracture. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:066127. [PMID: 16089840 DOI: 10.1103/physreve.71.066127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2004] [Indexed: 05/03/2023]
Abstract
Slow crack propagation in ductile, and in certain brittle materials, appears to take place via the nucleation of voids ahead of the crack tip due to plastic yields, followed by the coalescence of these voids. Postmortem analysis of the resulting fracture surfaces of ductile and brittle materials on the microm-mm and the nm scales, respectively, reveals self-affine cracks with anomalous scaling exponent zeta approximately = 0.8 in 3 dimensions and zeta approximately = 0.65 in 2 dimensions. In this paper we present an analytic theory based on the method of iterated conformal maps aimed at modelling the void formation and the fracture growth, culminating in estimates of the roughening exponents in 2 dimensions. In the simplest realization of the model we allow one void ahead of the crack, and address the robustness of the roughening exponent. Next we develop the theory further, to include two voids ahead of the crack. This development necessitates generalizing the method of iterated conformal maps to include doubly connected regions (maps from the annulus rather than the unit circle). While mathematically and numerically feasible, we find that the employment of the stress field as computed from elasticity theory becomes questionable when more than one void is explicitly inserted into the material. Thus further progress in this line of research calls for improved treatment of the plastic dynamics.
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Affiliation(s)
- Itai Afek
- Dept. of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, Israel
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44
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Itakura M, Kaburaki H, Arakawa C. Branching mechanism of intergranular crack propagation in three dimensions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:055102. [PMID: 16089585 DOI: 10.1103/physreve.71.055102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Indexed: 05/03/2023]
Abstract
We investigate the process of slow intergranular crack propagation by the finite element method model and show that branching is induced by partial arresting of a crack front owing to the geometrical randomness of grain boundaries. A possible scenario for the branching instability of crack propagation in a disordered continuous medium is also discussed.
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Affiliation(s)
- M Itakura
- Center for Promotion of Computational Science and Engineering, Japan Atomic Energy Research Institute, Higashiueno 6-9-3, Tokyo 110-0015, Japan
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45
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Xi XK, Zhao DQ, Pan MX, Wang WH, Wu Y, Lewandowski JJ. Fracture of brittle metallic glasses: brittleness or plasticity. PHYSICAL REVIEW LETTERS 2005; 94:125510. [PMID: 15903937 DOI: 10.1103/physrevlett.94.125510] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2004] [Indexed: 05/02/2023]
Abstract
We report a brittle Mg-based bulk metallic glass which approaches the ideal brittle behavior. However, a dimple structure is observed at the fracture surface by high resolution scanning electron microscopy, indicating some type of "ductile" fracture mechanism in this very brittle glass. We also show, from the available data, a clear correlation between the fracture toughness and plastic process zone size for various glasses. The results indicate that the fracture in brittle metallic glassy materials might also proceed through the local softening mechanism but at different length scales.
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Affiliation(s)
- X K Xi
- Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
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46
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Zapperi S, Nukala PKVV, Simunović S. Crack roughness and avalanche precursors in the random fuse model. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:026106. [PMID: 15783377 DOI: 10.1103/physreve.71.026106] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2004] [Revised: 11/22/2004] [Indexed: 05/24/2023]
Abstract
We analyze the scaling of the crack roughness and of avalanche precursors in the two-dimensional random fuse model by numerical simulations, employing large system sizes and extensive sample averaging. We find that the crack roughness exhibits anomalous scaling, as recently observed in experiments. The roughness exponents (zeta, zeta(loc) ) and the global width distributions are found to be universal with respect to the lattice geometry. Failure is preceded by avalanche precursors whose distribution follows a power law up to a cutoff size. While the characteristic avalanche size scales as s(0) approximately L(D) , with a universal fractal dimension D , the distribution exponent tau differs slightly for triangular and diamond lattices and, in both cases, it is larger than the mean-field (fiber bundle) value tau=5/2 .
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Affiliation(s)
- Stefano Zapperi
- INFM UdR Roma 1 and SMC, Dipartimento di Fisica, Università La Sapienza, Piazzale A. Moro 2, 00185 Roma, Italy
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47
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Bouchbinder E, Mathiesen J, Procaccia I. Roughening of fracture surfaces: the role of plastic deformation. PHYSICAL REVIEW LETTERS 2004; 92:245505. [PMID: 15245097 DOI: 10.1103/physrevlett.92.245505] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2003] [Indexed: 05/24/2023]
Abstract
Post mortem analysis of fracture surfaces of ductile and brittle materials on the microm-mm and the nm scales, respectively, reveal self-affine cracks with anomalous scaling exponent zeta approximately 0.8 in three dimensions and zeta approximately 0.65 in two dimensions. Attempts to use elasticity theory to explain this result failed, yielding exponent zeta approximately 0.5 up to logarithms. We show that when the cracks propagate via plastic void formations in front of the tip, followed by void coalescence, the void positions are positively correlated to yield exponents higher than 0.5.
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Affiliation(s)
- Eran Bouchbinder
- Department of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, Israel
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48
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Guin JP, Wiederhorn SM. Fracture of silicate glasses: ductile or brittle? PHYSICAL REVIEW LETTERS 2004; 92:215502. [PMID: 15245288 DOI: 10.1103/physrevlett.92.215502] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2003] [Indexed: 05/24/2023]
Abstract
Atomic force microscopy is used to investigate the possibility of cavity formation during crack growth in silicate glasses. Matching areas on both fracture surfaces were mapped and then compared. For silica glass, and soda-lime-silicate glass, the fracture surfaces matched to a resolution of better than 0.3 nm normal to the surface and 5 nm parallel to the surface. We could find no evidence for cavity formation in our study and suggest that completely brittle fracture occurs in glass.
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Affiliation(s)
- Jean-Pierre Guin
- National Institute of Standards and Technology, Gaithersburg, Maryland 20814, USA
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