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Rojas-Romero M, Medina-Cázares O, García-Rodríguez FJ, González-Vega A, Martínez-Ponce G, Gutiérrez-Juárez G. Accurate internal cavities and kissing bond sizing in metal plates by using the time-of-flight of laser-induced ultrasound waves. APPLIED OPTICS 2024; 63:3641-3647. [PMID: 38856550 DOI: 10.1364/ao.519588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 04/04/2024] [Indexed: 06/11/2024]
Abstract
This paper presents a nondestructive method for accurately identifying internal flaws in metal plates, which is crucial for ensuring structural integrity in safety-critical applications. The technique relies on analyzing laser-induced ultrasound (LIU) longitudinal wave time-of-flight, as demonstrated through a theoretical five-layer model. Experimental validation was conducted using a piezo-sensor in contact with a slab containing millimetric artificial cavities immersed in air, resulting in a discrepancy of 5.05%. In contrast, experiments performed in a water medium exhibited a lower discrepancy of 2.5%. (Discrepancy refers to differences between measurements obtained through an experimental time-of-flight analysis and caliper measurements.) The results obtained in water-based experiments affirm the accuracy of the proposed model. B-scan measurements and the five-layer model were utilized to generate 2D reconstructed images, enabling precise localization and sizing of cavities and kissing bonds between plates, finding an average size of kissing bond of 30 µm. In conclusion, the proposed five-layer model, based on a longitudinal wave time-of-flight analysis, provides a straightforward framework for an easy cavity and kissing bond measurements in metal plates.
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2
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Saurer M, Paltauf G, Nuster R. Efficient testing of weld seam models with radii of curvature in the millimeter range using laser ultrasound. ULTRASONICS 2024; 139:107292. [PMID: 38503034 DOI: 10.1016/j.ultras.2024.107292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 02/14/2024] [Accepted: 03/06/2024] [Indexed: 03/21/2024]
Abstract
Laser ultrasound is a widely used tool for industrial quality assurance when a contactless and fast method is required. In this work, we used a laboratory setup based on a confocal Fabry-Perot interferometer to examine weld seam models. The focus was placed on small samples with curved surfaces (small in the sense that the radius of curvature is comparable to the largest ultrasonic wavelength) and on efficient ways to detect the presence and volume of process pores, with the goal to transfer this method to industrial applications. In addition to this experimental method for investigating welds, a numerical method that models the experimental setup was implemented in MATLAB. For this purpose, first the thermal effects of the excitation process were taken into account by solving the thermal diffusion equation with an explicit scheme. Then, the elastodynamic equations were solved using the Elastodynamic Finite Integration Technique, taking into account the stresses induced by the excitation process. The B-Scans generated with this numerical model were compared with experimental B-Scans for simple test cases and good agreement was found. In a next step, the additional structures in the B-Scans resulting from air inclusions were identified and investigated with both methods using flat test specimens at first. Besides the direct echoes, structures from skimming surface waves and multiple reflections were visible. These additional structures are unwanted in defect reconstruction methods like the Synthetic Aperture Focusing Technique (SAFT) as they would lead to artifacts. In samples much larger than the largest ultrasound wavelength, however, these unwanted structures are still negligible in amplitude or can be well separated temporally, but for small samples this is no longer the case. As a result, reconstruction methods based on direct echoes like SAFT are difficult to apply. For many industrial applications, the reconstruction is not decisive at all, but only the knowledge of the total volume of process pores (TVPP). It is shown with both experimental and numerical methods, that this TVPP can be estimated from the variation in the B-Scans from various small weld seam models.
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Affiliation(s)
- Markus Saurer
- Department of Physics, University of Graz, Universitaetsplatz 5, Graz, 8010, Austria.
| | - Guenther Paltauf
- Department of Physics, University of Graz, Universitaetsplatz 5, Graz, 8010, Austria.
| | - Robert Nuster
- Department of Physics, University of Graz, Universitaetsplatz 5, Graz, 8010, Austria.
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3
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Zhang HB, Zhang CY, Cheng DJ, Zhou KL, Sun ZY. Detection Transformer with Multi-Scale Fusion Attention Mechanism for Aero-Engine Turbine Blade Cast Defect Detection Considering Comprehensive Features. SENSORS (BASEL, SWITZERLAND) 2024; 24:1663. [PMID: 38475200 DOI: 10.3390/s24051663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 02/17/2024] [Accepted: 02/29/2024] [Indexed: 03/14/2024]
Abstract
Casting defects in turbine blades can significantly reduce an aero-engine's service life and cause secondary damage to the blades when exposed to harsh environments. Therefore, casting defect detection plays a crucial role in enhancing aircraft performance. Existing defect detection methods face challenges in effectively detecting multi-scale defects and handling imbalanced datasets, leading to unsatisfactory defect detection results. In this work, a novel blade defect detection method is proposed. This method is based on a detection transformer with a multi-scale fusion attention mechanism, considering comprehensive features. Firstly, a novel joint data augmentation (JDA) method is constructed to alleviate the imbalanced dataset issue by effectively increasing the number of sample data. Then, an attention-based channel-adaptive weighting (ACAW) feature enhancement module is established to fully apply complementary information among different feature channels, and further refine feature representations. Consequently, a multi-scale feature fusion (MFF) module is proposed to integrate high-dimensional semantic information and low-level representation features, enhancing multi-scale defect detection precision. Moreover, R-Focal loss is developed in an MFF attention-based DEtection TRansformer (DETR) to further solve the issue of imbalanced datasets and accelerate model convergence using the random hyper-parameters search strategy. An aero-engine turbine blade defect X-ray (ATBDX) image dataset is applied to validate the proposed method. The comparative results demonstrate that this proposed method can effectively integrate multi-scale image features and enhance multi-scale defect detection precision.
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Affiliation(s)
- Han-Bing Zhang
- School of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
| | - Chun-Yan Zhang
- School of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
| | - De-Jun Cheng
- School of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
| | - Kai-Li Zhou
- School of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
| | - Zhi-Ying Sun
- School of Mechanical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China
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4
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Karuppasamy SS, Yang CH. Adapting the Time-Domain Synthetic Aperture Focusing Technique (T-SAFT) to Laser Ultrasonics for Imaging the Subsurface Defects. SENSORS (BASEL, SWITZERLAND) 2023; 23:8036. [PMID: 37836866 PMCID: PMC10575394 DOI: 10.3390/s23198036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/31/2023] [Accepted: 08/17/2023] [Indexed: 10/15/2023]
Abstract
Traditional ultrasonic testing uses a single probe or phased array probe to investigate and visualize defects by adapting certain imaging algorithms. The time-domain synthetic aperture focusing technique (T-SAFT) is an imaging algorithm that employs a single probe to scan along the test specimen in various positions, to generate inspection images with better resolution. Both the T-SAFT and phased array probes are contact methods with limited bandwidth. This work aims to combine the advantages of the T-SAFT and phased array in a noncontact way with the aid of laser ultrasonics. Here, a pulsed laser beam is employed to generate ultrasonic waves in both thermoelastic and ablation regimes, whereas the laser Doppler vibrometer is used to acquire the generated signals. These two lasers are focused on the test specimen and, to avoid the plasma and crater influence in the ablation regime, the transmission beam and reception beam are separated by 5 mm. By moving the test specimen with a step size of 0.5 mm, a 1D linear phased array (41 and 43 elements) with a pitch of 0.5 mm was synthesized, and three side-drilled holes (Ø 8 mm-thermoelastic regime, Ø 10 mm and Ø 2 mm-ablation regime) were introduced for inspection. The A-scan data obtained from these elements were processed via the T-SAFT algorithm to generate the inspection images in various grid sizes. The results showed that the defect reflections obtained in the ablation regime have better visibility than those from the thermoelastic regime. This is due to the high-amplitude signals obtained in the ablation regime, which pave the way for enhancing the pixel intensity of each grid. Moreover, the separation distance (5 mm) does not have any significant effect on the defect location during the reconstruction process.
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5
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Kim H, Balagopal B, Kerrigan S, Garcia N, Chow MY, Bourham M, Fang T, Jiang X. Noninvasive liquid level sensing with laser generated ultrasonic waves. ULTRASONICS 2023; 130:106926. [PMID: 36682290 DOI: 10.1016/j.ultras.2023.106926] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 12/29/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
This article proposes a noninvasive liquid level sensing technique using laser-generated ultrasound waves for nuclear power plant applications. Liquid level sensors play an important role of managing the coolant system safely and stably in the plant structure. Current sensing techniques are mostly intrusive, performing inside the fluidic structure, which is disadvantageous in terms of the regular maintenance of the plant system. Furthermore, typical intrusive sensors do not perform stably under varying environmental conditions such as temperature and radiation. In this study, sensing units are attached to the outer surface of a liquid vessel to capture guided ultrasound waves in a nonintrusive manner. The signal intensity of the guided wave dissipates when the signal interacts with the internal liquid media. The sensing mechanism is mathematically expressed as an index value to correlate the liquid level with the sensor signal. For the acoustic wave generation, laser-generated ultrasound was adopted instead of using typical contact type transducers. Following the simulation validation of the proposed concept, the performance of the developed sensor was confirmed through experimental results under elevated liquid temperature conditions. The nonlinear multivariable regression exhibited the best-fit to the datasets measured under the variable liquid level and temperature conditions.
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Affiliation(s)
- Howuk Kim
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA; Department of Mechanical Engineering, Inha University, Incheon 22212, South Korea
| | - Bharat Balagopal
- Department of Electric and Computer Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Sean Kerrigan
- Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Nicholas Garcia
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Mo-Yuen Chow
- Department of Electric and Computer Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Mohamed Bourham
- Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Tiegang Fang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Xiaoning Jiang
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695, USA.
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6
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Yang X, Zhang D, Wu B, Zhang K, Yang B, Wang Z, Wu X. Accurate Characterization of the Adhesive Layer Thickness of Ceramic Bonding Structures Using Terahertz Time-Domain Spectroscopy. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6972. [PMID: 36234313 PMCID: PMC9572604 DOI: 10.3390/ma15196972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 09/29/2022] [Accepted: 09/30/2022] [Indexed: 06/16/2023]
Abstract
Ceramic adhesive structures have been increasingly used in aerospace applications. However, the peaks of the signal on the upper and lower surface of the adhesive layer are difficult to measure directly due to the thin thickness of the adhesive layer and the effect of the attenuation dispersion of the ceramic layer. Thus, the existing non-destructive testing techniques have been ineffective in detecting adhesive quality. In this paper, the thickness of the adhesive layer is measured using terahertz time-domain spectroscopy. A sparse deconvolution method is proposed for the terahertz time-domain spectral signal of ceramic adhesive structures with different adhesive layer thicknesses. The results show that the methods proposed in this paper can realize the separation of reflection signals for glue layers with a thickness of 0.20 mm. By comparing with a wavelet denoising method and a modified covariance method (AR/MCM), the effectiveness of the sparse deconvolution method in estimating the thickness of the glue layer is demonstrated. This work will provide the theoretical and experimental basis for using terahertz time-domain spectroscopy to detect the homogeneity of ceramic adhesive structures.
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Affiliation(s)
- Xiuwei Yang
- Key Laboratory of Microwave Remote Sensing, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Automation, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
| | - Dehai Zhang
- Key Laboratory of Microwave Remote Sensing, National Space Science Center, Chinese Academy of Sciences, Beijing 100190, China
| | - Biyuan Wu
- Shandong Institute of Advanced Technology, Jinan 250100, China
- Basic Research Center, School of Power and Energy, Northwestern Polytechnical University, Xi’an 710072, China
| | - Kaihua Zhang
- Henan Key Laboratory of Infrared Materials and Spectrum Measures and Applications, School of Physics, Henan Normal University, Xinxiang 453007, China
| | - Bing Yang
- Centre for Advanced Laser Manufacturing (CALM), School of Mechanical Engineering, Shandong University of Technology, Zibo 255000, China
| | - Zhongmin Wang
- Institute of Automation, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250014, China
| | - Xiaohu Wu
- Shandong Institute of Advanced Technology, Jinan 250100, China
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7
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Han Y, Han Q, Wu N, Qian X, Shan M. Analysis of P wave induced second-order harmonic field at solid-fluid interface with potential matrix algorithm. ULTRASONICS 2022; 125:106789. [PMID: 35714398 DOI: 10.1016/j.ultras.2022.106789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Revised: 05/22/2022] [Accepted: 06/05/2022] [Indexed: 06/15/2023]
Abstract
Based on the second-order harmonic potential theory, the characteristics of the second-order harmonic field generated at the solid-liquid interface induced by P wave incidence are analyzed. A planar model of the solid-liquid interface is established to study the variation of the second-order displacement field versus the incident angles. The homogeneous solution coefficient matrix, refraction and reflection coefficient matrix are introduced. According to the boundary conditions and Lagrange's various parameters method, the second-order displacement field is obtained, and its dependence on the solid-liquid interface is investigated. The different effects of boundary on the tangential displacement and normal displacement are demonstrated. Numerical simulation shows that the complete solution varies slightly at the incident angle, and the tangential displacement and the normal displacement change sharply at a mutation angle θω due to the boundary effect.
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Affiliation(s)
- Yufeng Han
- College of Internet of Things Engineering, Hohai University, Changzhou 213022, China
| | - Qingbang Han
- College of Internet of Things Engineering, Hohai University, Changzhou 213022, China.
| | - Ning Wu
- College of Internet of Things Engineering, Hohai University, Changzhou 213022, China
| | - Xintong Qian
- College of Internet of Things Engineering, Hohai University, Changzhou 213022, China
| | - Minglei Shan
- College of Internet of Things Engineering, Hohai University, Changzhou 213022, China
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8
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Bai L, Liu M, Liu N, Su X, Lai F, Xu J. Dimensionality reduction of ultrasonic array data for characterization of inclined defects based on supervised locality preserving projection. ULTRASONICS 2022; 119:106625. [PMID: 34739950 DOI: 10.1016/j.ultras.2021.106625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 09/21/2021] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
Ultrasonic arrays are increasingly used for inspection of the structural components in non-destructive testing (NDT) applications. The ultrasonic array data can be processed to form high-resolution images for detection and localization of defects. Alternatively, the scattering matrix can be extracted from the full matrix of array data and used for defect characterization if the defect size is small (i.e., comparable to an ultrasonic wavelength). This paper studies the dimensionality reduction problem of scattering matrix databases. In particular, we focus on accurate characterization of inclined defects for which previous approaches based on principal component analysis (PCA) yielded high characterization uncertainty. We propose a supervised approach based on locality preserving projection (LPP) and introduce noise constraints to the objective function of LPP. In simulation, the proposed approach is shown to produce a well-resolved defect manifold for 45°ellipses. Characterization results obtained using the simulated noisy measurements of four 60°ellipses confirm the performance improvement of LPP over PCA. In experiments, three 60°ellipses and two surface-breaking cracks have been characterized. On average, the root-mean-square (RMS) sizing error given by the LPP approach is 39.0% lower compared to PCA for the ellipses and 11.1% lower for the surface-breaking cracks.
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Affiliation(s)
- Long Bai
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Minkang Liu
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Nanxin Liu
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Xin Su
- Southwest Institution of Electronic Technology, Chengdu 610036, China.
| | - Fuyao Lai
- Southwest Institution of Electronic Technology, Chengdu 610036, China.
| | - Jianfeng Xu
- State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
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9
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Xiao J, Chen J, Yu X, Lisevych D, Fan Z. Remote characterization of surface slots by enhanced laser-generated ultrasonic Rayleigh waves. ULTRASONICS 2022; 119:106595. [PMID: 34638003 DOI: 10.1016/j.ultras.2021.106595] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/18/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
Characterization of surface features is essential in many industrial applications, especially for features with large depths, high aspect ratios or under extreme conditions. This work presents a non-contact method to characterize surface slots with large lengths using ultrasonic Rayleigh waves generated by a pulsed laser. A delay-and-sum superposition technique is applied to enhance the signal to noise ratio of transmitted Rayleigh waves. The length of the slot can be calculated from the time-of-flight information of Rayleigh waves without any prior knowledge of its orientation, width or aspect ratio. Both numerical simulations and experiments are conducted to demonstrate the proposed method, showing excellent performance. Furthermore, mode conversion has been studied to understand its impact on the reconstruction accuracy. Given the non-contact feature of the laser ultrasonic technique, the proposed method provides a simple and feasible avenue for the rapid characterisation of normal and angled surface features with high aspect ratio in extreme environments.
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Affiliation(s)
- Jing Xiao
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; Institute of High Performance Computing, A*STAR (Agency for Science, Technology and Research), Singapore 138632, Singapore
| | - Jian Chen
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; The State Key Laboratory of Fluid Power and Mechatronic Systems, School of Mechanical Engineering, Zhejiang University, Hangzhou 310027, China
| | - Xudong Yu
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore; School of Astronautics, Beihang University, Beijing 100191, China
| | - Danylo Lisevych
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Zheng Fan
- School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
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10
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Current Trends in Integration of Nondestructive Testing Methods for Engineered Materials Testing. SENSORS 2021; 21:s21186175. [PMID: 34577382 PMCID: PMC8473222 DOI: 10.3390/s21186175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 09/03/2021] [Accepted: 09/08/2021] [Indexed: 11/17/2022]
Abstract
Material failure may occur in a variety of situations dependent on stress conditions, temperature, and internal or external load conditions. Many of the latest engineered materials combine several material types i.e., metals, carbon, glass, resins, adhesives, heterogeneous and nanomaterials (organic/inorganic) to produce multilayered, multifaceted structures that may fail in ductile, brittle, or both cases. Mechanical testing is a standard and basic component of any design and fabricating process. Mechanical testing also plays a vital role in maintaining cost-effectiveness in innovative advancement and predominance. Destructive tests include tensile testing, chemical analysis, hardness testing, fatigue testing, creep testing, shear testing, impact testing, stress rapture testing, fastener testing, residual stress measurement, and XRD. These tests can damage the molecular arrangement and even the microstructure of engineered materials. Nondestructive testing methods evaluate component/material/object quality without damaging the sample integrity. This review outlines advanced nondestructive techniques and explains predominantly used nondestructive techniques with respect to their applications, limitations, and advantages. The literature was further analyzed regarding experimental developments, data acquisition systems, and technologically upgraded accessory components. Additionally, the various combinations of methods applied for several types of material defects are reported. The ultimate goal of this review paper is to explain advanced nondestructive testing (NDT) techniques/tests, which are comprised of notable research work reporting evolved affordable systems with fast, precise, and repeatable systems with high accuracy for both experimental and data acquisition techniques. Furthermore, these advanced NDT approaches were assessed for their potential implementation at the industrial level for faster, more accurate, and secure operations.
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11
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Veira Canle D, Mäkinen J, Blomqvist R, Gritsevich M, Salmi A, Hæggström E. Defect localization by an extended laser source on a hemisphere. Sci Rep 2021; 11:15191. [PMID: 34312423 PMCID: PMC8313693 DOI: 10.1038/s41598-021-94084-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/05/2021] [Indexed: 11/16/2022] Open
Abstract
The primary goal of this study is to localize a defect (cavity) in a curved geometry. Curved topologies exhibit multiple resonances and the presence of hotspots for acoustic waves. Launching acoustic waves along a specific direction e.g. by means of an extended laser source reduces the complexity of the scattering problem. We performed experiments to demonstrate the use of a laser line source and verified the experimental results in FEM simulations. In both cases, we could locate and determine the size of a pit in a steel hemisphere which allowed us to visualize the defect on a 3D model of the sample. Such an approach could benefit patients by enabling contactless inspection of acetabular cups.
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Affiliation(s)
- Daniel Veira Canle
- Department of Physics, Division of Material Physics, Faculty of Science, University of Helsinki, P.O.B. 64, 00014, Helsinki, Finland.
| | - Joni Mäkinen
- Department of Physics, Division of Material Physics, Faculty of Science, University of Helsinki, P.O.B. 64, 00014, Helsinki, Finland
| | - Richard Blomqvist
- Department of Physics, Division of Material Physics, Faculty of Science, University of Helsinki, P.O.B. 64, 00014, Helsinki, Finland
| | - Maria Gritsevich
- Department of Physics, Division of Material Physics, Faculty of Science, University of Helsinki, P.O.B. 64, 00014, Helsinki, Finland.,Finnish Geospatial Research Institute, Geodeetinrinne 2, 02430, Masala, Finland.,Institute of Physics and Technology, Ural Federal University, Mira Str. 19, 620002, Ekaterinburg, Russia
| | - Ari Salmi
- Department of Physics, Division of Material Physics, Faculty of Science, University of Helsinki, P.O.B. 64, 00014, Helsinki, Finland
| | - Edward Hæggström
- Department of Physics, Division of Material Physics, Faculty of Science, University of Helsinki, P.O.B. 64, 00014, Helsinki, Finland
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12
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Vangi D, Banelli L, Gulino MS. Interference-based amplification for CW laser-induced photoacoustic signals. ULTRASONICS 2021; 110:106270. [PMID: 33130361 DOI: 10.1016/j.ultras.2020.106270] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 08/31/2020] [Accepted: 10/04/2020] [Indexed: 06/11/2023]
Abstract
Thanks to their low cost, compactness and suitability of use in industrial environments, CW lasers represent a viable alternative to more traditional pulsed lasers for non-contact inspection of structures, both under static and working conditions. However, the lower energy density typically reached by CW lasers requires adequate attention to obtain ultrasonic signals with sufficient amplitude. CW lasers can be modulated by TTL sequences with different duty cycles to constructively use the excitation of a double ultrasonic wave, occurring when the laser is both turned on and off. An appropriate choice in terms of number and spacing of the TTL pulses allows for the optimization of the ultrasonic response from the excitation standpoint: an increase in the amplitude of the ultrasound is enabled, and its frequency band modified. Such a solution allows to better adapt the ultrasonic wave to the receiver band, maximizing the global efficiency. In this work, the influence of the employed modulation sequence on the ultrasonic signal is analysed; by the TTL optimization proposed, application of the technique to the exemplary case of a rail represents a first implementation of CW lasers to the inspection of an industrial component.
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Affiliation(s)
- Dario Vangi
- Department of Industrial Engineering of Florence, Università degli Studi di Firenze, Via di Santa Marta 3, 50139 Firenze, Italy
| | - Luca Banelli
- Department of Industrial Engineering of Florence, Università degli Studi di Firenze, Via di Santa Marta 3, 50139 Firenze, Italy
| | - Michelangelo-Santo Gulino
- Department of Industrial Engineering of Florence, Università degli Studi di Firenze, Via di Santa Marta 3, 50139 Firenze, Italy.
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13
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Zhang J, Wu J, Zhao X, Yuan S, Ma G, Li J, Dai T, Chen H, Yang B, Ding H. Laser ultrasonic imaging for defect detection on metal additive manufacturing components with rough surfaces. APPLIED OPTICS 2020; 59:10380-10388. [PMID: 33361969 DOI: 10.1364/ao.405284] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/20/2020] [Indexed: 06/12/2023]
Abstract
Defects or discontinuities are inevitable during the melting and consolidation process of metal additive manufacturing. Online inspection of microdefects during the processing of layer-by-layer fusion is urgently needed for quality control. In this study, the laser ultrasonic C-scan imaging system is established to detect the surface defects of selective laser melting (SLM) samples that have a different surface roughness. An autosizing method based on the maximum correlation coefficient and lag time is proposed to accurately measure the defect length. The influences of the surface roughness on the laser ultrasound signal-to-noise ratio distribution and defect sizing accuracy are also studied. The results indicate that the proposed system can detect notches with a depth of 50 µm and holes with a diameter of 50 µm, comparable in size to raw powder particles. The average error for the length measurement can reach 1.5% if the notch is larger than 2 mm. Meanwhile, the sizing error of a 1 mm length notch is about 9%. In addition, there is no need to remove the rough surface of the as-built SLM samples during the detection process. Hence, we propose that the laser ultrasonic imaging system is a potential method for online inspection of metal additive manufacturing.
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14
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Directional Ultrasound Source for Solid Materials Inspection: Diffraction Management in a Metallic Phononic Crystal. SENSORS 2020; 20:s20216148. [PMID: 33137989 PMCID: PMC7662396 DOI: 10.3390/s20216148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 10/22/2020] [Accepted: 10/26/2020] [Indexed: 11/17/2022]
Abstract
In this work, we numerically investigate the diffraction management of longitudinal elastic waves propagating in a two-dimensional metallic phononic crystal. We demonstrate that this structure acts as an "ultrasonic lens", providing self-collimation or focusing effect at a certain distance from the crystal output. We implement this directional propagation in the design of a coupling device capable to control the directivity or focusing of ultrasonic waves propagation inside a target object. These effects are robust over a broad frequency band and are preserved in the propagation through a coupling gel between the "ultrasonic lens" and the solid target. These results may find interesting industrial and medical applications, where the localization of the ultrasonic waves may be required at certain positions embedded in the object under study. An application example for non-destructive testing with improved results, after using the ultrasonic lens, is discussed as a proof of concept for the novelty and applicability of our numerical simulation study.
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