Experimental Mechanics最新文献

{"title":"Speckle Image Restoration for DIC Measurement Under Non-Uniform Illumination Based on Deep Learning Model","authors":"C. Zhang,&nbsp;X. Shao,&nbsp;D. Zhang","doi":"10.1007/s11340-026-01280-8","DOIUrl":"10.1007/s11340-026-01280-8","url":null,"abstract":"<div><h3>Background</h3><p>Shadows caused by non-uniform illumination can introduce significant errors in digital image correlation (DIC) measurements. The deep learning methods offer a good solution for image restoration. However, a dedicated deep learning approach for speckle images restoration in DIC measurement still requires further investigation.</p><h3>Objective</h3><p>For this purpose, based on the quality assessment criterion of speckle images, this study aims to develop an improved Generative Adversarial Network (GAN)-based model for restoration of speckle images to eliminate the interference of non-uniform illumination on DIC measurement.</p><h3>Methods</h3><p>Technically, the model consists of a generator with skip connections and multi-resolution discriminators to balance both global structures and fine details. In context of speckle images restoration, a speckle quality assessment module derived from the Gray-Level Co-occurrence Matrix (GLCM) is incorporated into the training, thereby guiding the generator to synthesize speckle patterns that more faithfully approximate real images in terms of brightness, contrast, and detail fidelity. In addition, a dataset is constructed with speckle images degraded by various non-uniform illumination and corresponding clear references.</p><h3>Results</h3><p>The Speckle-GAN model is evaluated with conventional image restoration methods. Both qualitative and quantitative evaluations demonstrate its superior capability in restoring clarity of speckle images degraded by non-uniform illumination shadows. Furthermore, DIC experiments under artificial non-uniform lighting are conducted, where the measurement errors are significantly reduced by applying the proposed method.</p><h3>Conclusions</h3><p>The proposed method effectively mitigates illumination-induced degradation in speckle images, thereby improving accuracy and robustness of DIC under challenging lighting conditions.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 4","pages":"627 - 645"},"PeriodicalIF":2.4,"publicationDate":"2026-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Analysis of Energy Dissipation in Structural Adhesive Joints: Relationship Between Hysteresis and Modal Damping","authors":"J. de J Villalobos Luna,&nbsp;P. Lopez Cruz,&nbsp;D. F. Ledezma Ramírez,&nbsp;J. G. Puente Córdova","doi":"10.1007/s11340-026-01278-2","DOIUrl":"10.1007/s11340-026-01278-2","url":null,"abstract":"<div><h3>Background</h3><p>Researchers have studied shift damping in structures because it is more sensitive than shift frequencies and can indicate structural damage. Changes in hysteresis damping also suggest modifications within structures during cyclic tests. However, the relationship between these two approaches has not been documented, presenting a potential opportunity for research into damage indicators in structural health monitoring.</p><h3>Objective</h3><p>This study examines energy dissipation during the evolution of cycling tests in structural adhesive joints to validate the equivalence between modal and hysteresis damping.</p><h3>Methods</h3><p>Experimental analysis was conducted on test coupons of single-lap adhesive joints mounted on aluminum substrates. A universal cyclic testing machine and vibration data acquisition systems were employed. Hysteresis loops were measured to estimate dissipation energy across the entire cycling process until failure. Concurrently, the frequency response function was measured using an impact hammer, and modal damping was estimated via the half-power method during postprocessing.</p><h3>Results</h3><p>The damping progression followed a bathtub-like behavior, which could predict the residual life of the joints. Changes in measured damping indicate that hysteresis-estimated damping and the sum of modal damping across different resonant frequencies exhibit similar patterns during the cycling process.</p><h3>Conclusions</h3><p>An experimental relationship between hysteresis damping and modal damping during cyclic testing has been established. These findings support the utility of modal and hysteresis damping estimations in enhancing structural health monitoring techniques.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 4","pages":"615 - 626"},"PeriodicalIF":2.4,"publicationDate":"2026-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147738058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Cover: Efficient Identification of Stiffness Parameters in Hyperelastic Models for Coated Woven Fabrics Based on a Single Experiment - Comparative Study Using Real Experiment by L. Makhool, D.-O. Cloidt, D. Balzani","authors":"","doi":"10.1007/s11340-026-01274-6","DOIUrl":"10.1007/s11340-026-01274-6","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 3","pages":"443 - 443"},"PeriodicalIF":2.4,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147560413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fusion-Restoration Image Processing Algorithm to Improve the High-Temperature Deformation Measurement","authors":"B. Guan,&nbsp;D. Tan,&nbsp;J. Tao,&nbsp;A. Su,&nbsp;Y. Shang,&nbsp;Q. Yu","doi":"10.1007/s11340-026-01270-w","DOIUrl":"10.1007/s11340-026-01270-w","url":null,"abstract":"<div><h3>Background</h3><p>In the deformation measurement of high-temperature structures, image degradation caused by thermal radiation and random errors introduced by heat haze restrict the accuracy and effectiveness of deformation measurement.</p><h3>Objective</h3><p>The purpose of this study is to suppress thermal radiation and heat haze using fusion-restoration image processing methods, thereby improving the accuracy and effectiveness of Digital Image Correlation (DIC) in the measurement of high-temperature deformation.</p><h3>Methods</h3><p>For image degradation caused by thermal radiation, based on the image layered representation, the image is decomposed into positive and negative channels for parallel processing, and then optimized for quality by multi-exposure image fusion. To counteract the high-frequency, random errors introduced by heat haze, we adopt the Feature Similarity Index (FSIM) as the objective function to guide the iterative optimization of model parameters, and the grayscale average algorithm is applied to equalize anomalous gray values, thereby reducing measurement error.</p><h3>Results</h3><p>The proposed multi-exposure image fusion algorithm effectively suppresses image degradation caused by complex illumination conditions, boosting the effective computation area from 26 % to 50 % for under-exposed images and from 32 % to 40 % for over-exposed images without degrading measurement accuracy in the experiment. Meanwhile, the image restoration combined with the grayscale average algorithm reduces static thermal deformation measurement errors. The error in <span>(varepsilon _{xx})</span> is reduced by 85.3%, while the errors in <span>(varepsilon _{yy})</span> and <span>(gamma _{xy})</span> are reduced by 36.0% and 36.4%, respectively.</p><h3>Conclusions</h3><p>We present image processing methods to suppress the interference of thermal radiation and heat haze in high-temperature deformation measurement using DIC. The experimental results verify that the proposed method can effectively improve image quality, reduce deformation measurement errors, and has potential application value in thermal deformation measurement.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 4","pages":"591 - 602"},"PeriodicalIF":2.4,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Localized Deformation of Human Tooth","authors":"R. Liang,&nbsp;Z. Xu,&nbsp;M. Liu,&nbsp;J. Jiang,&nbsp;F. Yang","doi":"10.1007/s11340-026-01272-8","DOIUrl":"10.1007/s11340-026-01272-8","url":null,"abstract":"<div><h3>Background</h3><p>Mechanical properties of human teeth are key for understanding functions and developing restorative materials, and the distribution of micromechanical properties across the enamel-dentine junction has been rarely explored by micro-scratch tests, especially under clinically-relevant forces.</p><h3>Objective</h3><p>This study aims to explore the localized mechanical responses of the enamel and dentine of a human molar by both nanoindentation and micro-scratch methods.</p><h3>Methods</h3><p>Nanoindentation and micro-scratch tests were carried out on enamel and dentine of a human molar.</p><h3>Results</h3><p>The mechanical properties (e.g., contact modulus, indentation hardness, wear resistance, plastic deformation resistance, elastic strain capacity, and brittleness index) of enamel and dentine were measured and compared: the enamel exhibits superior mechanical properties (e.g., higher contact modulus, indentation hardness, wear/plastic deformation resistance, and elastic strain capacity) compared to dentine; and dentine has a much smaller brittleness index than enamel.</p><h3>Conclusions</h3><p>The superior mechanical properties of enamel enable human teeth to maintain bio-functionality in harsh environment, and the smaller brittleness index of dentine allows teeth to absorb mechanical energy from repeated contact/impact without causing structural damages.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 4","pages":"603 - 614"},"PeriodicalIF":2.4,"publicationDate":"2026-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-026-01272-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147737911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient Identification of Stiffness Parameters in Hyperelastic Models for Coated Woven Fabrics Based on a Single Experiment - Comparative Study Using Real Experiment","authors":"L. Makhool,&nbsp;D.-O. Cloidt,&nbsp;D. Balzani","doi":"10.1007/s11340-025-01257-z","DOIUrl":"10.1007/s11340-025-01257-z","url":null,"abstract":"<div><h3>Background</h3><p>Determining the optimal number of classical biaxial tests and the selection of appropriate stress ratios for characterizing the complex behavior of coated woven fabrics is a challenge. Thus, the reliability of models calibrated using these homogeneous tests in predicting engineering structural performance may be limited.</p><h3>Objective</h3><p>A recently proposed experimental-numerical approach has been shown in a feasibility study to offer a new perspective for the characterization of nonlinear anisotropic thin materials (Makhool and Balzani Experimental Mech 64:353–375 2025). The goal here is not only to validate the robustness and efficiency of this much less expensive identification framework using real experimental data from a single experiment on coated woven fabrics, but also to demonstrate that the parameters obtained based thereon may even improve the accuracy of structural analysis.</p><h3>Methods</h3><p>On the basis of the Equilibrium Gap Method, provided that the material parameters are linear in the constitutive equations, a quadratic objective function is formulated, enabling a unique identification. Key of this framework are inhomogeneous full-field kinematics obtained from a single experimental setup designed to excite all essential deformation modes in the material model. Prior to incorporating the data into the discretized equilibrium equations, a pre-processing step is conducted, involving interpolation and extrapolation of the displacements on the scattered speckle pattern to map the values onto the computational grid.</p><h3>Results</h3><p>The analysis validates the efficiency of the framework for the identification of material parameters using a single inhomogeneous displacement field captured by Digital Image Correlation. Further, through examining a boundary value problem replicating a modified experimental setup, highly predictive numerical results that closely match experimental data are obtained incorporating the identified parameters. In contrast, the acquired response using parameters derived from a classical fitting method shows notable deviations. The difference becomes particularly significant for a complex roof structure investigated as an example engineering problem.</p><h3>Conclusion</h3><p>Based on real experiments, the experimental-numerical framework turns out to indeed allow for an efficient and unique identification of material parameters in hyperelastic models for coated woven fabrics. Since a variety of different stress-ratios are integrated at once in the experiment by considering inhomogeneous kinematics, also an improved accuracy in structural simulations is found.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 3","pages":"529 - 549"},"PeriodicalIF":2.4,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-025-01257-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Loading Rate Dependent Mode I Fracture in Fibrous Cementitious Composites: Insights from Digital Image Correlation Method","authors":"R. Vidya Sagar,&nbsp;S. A. Samadhan,&nbsp;N. Gupta","doi":"10.1007/s11340-025-01260-4","DOIUrl":"10.1007/s11340-025-01260-4","url":null,"abstract":"<div><h3>Background</h3><p>The background of this study lies in understanding the mechanical behavior of fibrous cementitious composites under Mode I fracture at varying loading rates, which is primarily governed by the dynamic interaction between the steel fibers and the cementitious matrix. Although steel fiber reinforced concrete is engineered to enhance ductility and crack resistance, overall performance may change under quasistatic to moderate loading due to sensitivity to loading rate effects.</p><h3>Objective</h3><p>The objective of this study is to address the existing research gap by investigating the influence of the loading rate on key fracture parameters, including fracture energy, ultimate peak load, crack mouth opening displacement at peak load, and mid-span deflection. The evolution of crack propagation was analyzed through digital image correlation, enabling the computation of fictitious crack tip displacements.</p><h3>Methods</h3><p>An experimental program involving three-point bending tests was conducted on notched beams with varying steel fiber volume fractions (0%, 0.5%, 1%, and 1.5%) to assess the effect of loading rate on the fracture behavior. Results showed a clear loading rate dependency in both plain and fibrous cementitious composites.</p><h3>Results</h3><p>The analysis shows that for a given crack mouth opening displacement, higher loading rates result in greater fictitious crack tip advancement, highlighting the rate-sensitive nature of fracture processes in both plain and steel fiber reinforced concrete.</p><h3>Conclusions</h3><p>These findings contribute to an understanding of the loading rate dependent fracture behavior of fibrous cementitious composites and offer insights for the design and analysis of structural elements subjected to various loading conditions.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 3","pages":"515 - 527"},"PeriodicalIF":2.4,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147561100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Cover: Design and Validation of a Symmetric Drop Weight System for Tensile Intermediate Strain Rate Characterization","authors":"","doi":"10.1007/s11340-026-01264-8","DOIUrl":"10.1007/s11340-026-01264-8","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 2","pages":"221 - 221"},"PeriodicalIF":2.4,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147340744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal Pose Guidance for Stereo Calibration in 3D Deformation Measurement","authors":"D. Tan,&nbsp;S. Liang,&nbsp;B. Li,&nbsp;B. Guan,&nbsp;A. Su,&nbsp;Y. Lin,&nbsp;D. Zhang,&nbsp;M. Wan,&nbsp;Z. Liu,&nbsp;C. Wang,&nbsp;J. Zhu,&nbsp;Z. Li,&nbsp;Y. Shang,&nbsp;Q. Yu","doi":"10.1007/s11340-025-01255-1","DOIUrl":"10.1007/s11340-025-01255-1","url":null,"abstract":"<div><h3>Background</h3><p>Stereo optical measurement techniques, such as digital image correlation (DIC), are widely used in 3D deformation measurement as non-contact, full-field measurement methods, in which stereo calibration is a crucial step. However, current stereo calibration methods lack intuitive optimal pose guidance, leading to inefficiency and suboptimal accuracy in deformation measurements.</p><h3>Objective</h3><p>The aim of this study is to develop an interactive calibration framework that automatically generates the next optimal pose, enabling high-accuracy stereo calibration for 3D deformation measurement.</p><h3>Methods</h3><p>We propose a pose optimization method that introduces joint optimization of relative and absolute extrinsic parameters, with the minimization of the covariance matrix trace adopted as the loss function to solve for the next optimal pose. Integrated with this method is a user-friendly graphical interface, which guides even non-expert users to capture qualified calibration images.</p><h3>Results</h3><p>Our proposed method demonstrates superior efficiency (requiring fewer images) and accuracy (demonstrating lower measurement errors) compared to random pose, while maintaining robustness across varying FOVs. In the thermal deformation measurement tests (500–700<span>(^{circ })</span>C) on an S-shaped specimen, the results exhibit high agreement with finite element analysis (FEA) simulations in both deformation magnitude and evolutionary trends.</p><h3>Conclusions</h3><p>We present a pose guidance method for high-precision stereo calibration in 3D deformation measurement. The simulation experiments, real-world experiments, and thermal deformation measurement applications all demonstrate the significant application potential of our proposed method in the field of 3D deformation measurement.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 3","pages":"501 - 514"},"PeriodicalIF":2.4,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147559661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Celebrating Prof. Cesar Sciammarella’s 100th Anniversary and Contributions","authors":"C. Furlong,&nbsp;H. Espinosa,&nbsp;K.-S. Kim,&nbsp;G. A. Shaw,&nbsp;M. Sutton","doi":"10.1007/s11340-025-01263-1","DOIUrl":"10.1007/s11340-025-01263-1","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 1","pages":"5 - 6"},"PeriodicalIF":2.4,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}