Experimental Mechanics最新文献

{"title":"On the Cover: A Novel Method to In-Situ Characterize Fatigue Crack Growth Behavior of Nickel Based Superalloys by Laser Thermography","authors":"","doi":"10.1007/s11340-024-01132-3","DOIUrl":"10.1007/s11340-024-01132-3","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"1 - 1"},"PeriodicalIF":2.0,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994517","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":"Physics-Informed Neural Network Based Digital Image Correlation Method","authors":"B. Li,&nbsp;S. Zhou,&nbsp;Q. Ma,&nbsp;S. Ma","doi":"10.1007/s11340-024-01139-w","DOIUrl":"10.1007/s11340-024-01139-w","url":null,"abstract":"<div><h3>Background</h3><p>Deep Learning-based Digital Image Correlation (DL-DIC) approaches take advantages such as pixel-wise calculation in a full-automatic manner without user's input and improved accuracy in non-uniform deformation measurements. However, DL-DIC still faces accuracy limitations due to the lack of high-precision real-world training data in supervised-learning methods and the need for smoothing noisy solutions in unsupervised-learning methods.</p><h3>Objective</h3><p>This paper proposes a DIC solution method based on Physics-Informed Neural Networks (PINN), called PINN-DIC, to address deformation measurement challenges of current DL-DIC in practical applications.</p><h3>Methods</h3><p>PINN-DIC utilizes a fully connected neural network, with regularized spatial coordinate field as input and displacement field as output. It applies the photometric consistency assumption as a physical constraint, using grayscale differences between predicted and actual deformed images to construct a loss function for iterative optimization of the displacement field. Additionally, a warm-up stage is designed to assist in iterative optimization, allowing PINN-DIC to achieve high accuracy in analyzing both uniform and non-uniform displacement fields.</p><h3>Results</h3><p>PINN-DIC, validated through simulations and real experiments, not only maintained the advantages of other DL-DIC methods but also demonstrated superior performance in achieving higher accuracy than conventional unsupervised DIC and handling irregular boundaries with adjusting the input coordinate field.</p><h3>Conclusions</h3><p>PINN-DIC is an unsupervised method that takes a regularized coordinate field (instead of speckle images) as input and achieves higher accuracy in deformation field results with a simple network. It introduces a novel approach to DL-DIC, enhancing performance in complex measurement scenarios.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 2","pages":"221 - 240"},"PeriodicalIF":2.0,"publicationDate":"2025-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513336","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":"Editorial: Message from the Incoming Editor-in-Chief","authors":"J. Wang","doi":"10.1007/s11340-024-01133-2","DOIUrl":"10.1007/s11340-024-01133-2","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"3 - 3"},"PeriodicalIF":2.0,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994647","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":"X-Ray Tomography-Based Characterization of the Porosity Evolution in Composites Manufactured by Fused Filament Fabrication","authors":"A. Lingua,&nbsp;F. Sosa-Rey,&nbsp;N. Piccirelli,&nbsp;D. Therriault,&nbsp;M. Lévesque","doi":"10.1007/s11340-024-01124-3","DOIUrl":"10.1007/s11340-024-01124-3","url":null,"abstract":"<div><h3>Background</h3><p>Fused filament fabrication delivers composites with incomplete interface bonding prone to delaminate under loading due to the non-isothermal molecular entanglement during deposition.</p><h3>Objective</h3><p>We aim to localize the mesoscale porosity in 3D-printed composites and quantify its volumetric growth under loading to investigate whether incomplete filament adhesion can lead to delamination.</p><h3>Methods</h3><p>We measured the porosity volumic content by X-ray tomography testing. To distinguish between damage nucleated at the crack tip and mesoscale interface delamination, we quantified the local, 3D strain concentration region size at the crack tip by 2D digital image correlation of slice images over orthogonal planes.</p><h3>Results</h3><p>Through image segmentation, we observed that the mesoscale porosity resulting from the deposition process clustered at the filament interfaces and doubled from roughly 7% to 14% from an applied opening load of 700 N to 1400 N due to the stress concentration at the filament interfaces. Digital image correlation emphasized the strain concentration over a reduced area at the notch, up to the damage nucleation for an applied load of 1400 N, before the sudden brittle failure.</p><h3>Conclusion</h3><p>The presented contactless characterization technique emphasizes that mesoscale porosity concentrates at the filament interface, which is a critical delamination nucleation site under loading. This fracture mechanism is even more severe for high-performance composites such as carbon fiber reinforced PEEK.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 4","pages":"455 - 466"},"PeriodicalIF":2.0,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919295","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":"Dissimilar Material Joining via Interlocking Metasurfaces","authors":"B. Elbrecht,&nbsp;B. Young,&nbsp;B. Clark,&nbsp;P. Noell","doi":"10.1007/s11340-024-01127-0","DOIUrl":"10.1007/s11340-024-01127-0","url":null,"abstract":"<div><h3>Background</h3><p>The integration of dissimilar materials poses a significant challenge in engineering, necessitating innovative solutions for robust and reliable joining. Interlocking metasurfaces (ILMs) are a new joining technology comprising arrays of autogenous features patterned across two surfaces that interlock to form robust structural joints.</p><h3>Objective</h3><p>This study elucidates the factors influencing the tensile performance of ILM joints formed between dissimilar materials.</p><h3>Methods</h3><p>We employed parametric optimization to identify optimal unit cell geometries for maximal yield strength based on the hypothesis that the elastic tensile properties of the materials are the primary determinants of tensile performance. Experimental validation was performed by mechanically testing the theorized optimal ILM geometry and a range of ILM geometries to capture the overall behavior trends of joints between two additively manufactured polymers, VeroPureWhite (VW) and RGDA8430-DM (8430).</p><h3>Results</h3><p>Experimental validation of optimized designs revealed that additional factors, e.g. flexural strength and localized plasticity, also strongly influenced the tensile performance of T-slot ILMs joining dissimilar materials. The proposed optimal design remained the best performer.</p><h3>Conclusions</h3><p>This study demonstrates the viability of ILMs as a joining method for dissimilar materials. ILMs can join dissimilar materials with no loss in joint yield strength compared to joints composed solely of the weaker of the two constitutive materials. ILMs demonstrated their potential as a versatile and effective joining technology in diverse engineering applications.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 4","pages":"443 - 453"},"PeriodicalIF":2.0,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143918937","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":"Research on a New Exponential Function Weighted Averaging Method Used for Full-Gradient Strain Measurement of DIC","authors":"X. Song,&nbsp;C. Zhou,&nbsp;K. Xiong","doi":"10.1007/s11340-024-01125-2","DOIUrl":"10.1007/s11340-024-01125-2","url":null,"abstract":"<div><h3>Background</h3><p>In the implementation of Digital Image Correlation (DIC), several post-processing methods have been developed to calculate reliable strain field. Nevertheless, achieving effective and easy-to-implement strain measurement for full-gradient strain fields continues to be a challenge.</p><h3>Objective</h3><p>The widely used pointwise least square (PLS) method is hard to get a balance between smoothing and accuracy when dealing with different deformation fields. A large strain calculation window may lead to over-smoothing, whereas a small strain calculation window may be insufficient to suppress noise.</p><h3>Methods</h3><p>A new exponential function and the exponential function weighted averaging (EFWA) method are proposed. The shape of the exponential function can be either sharp-topped or flat-topped, allowing the EFWA method to either preserve or smooth the original strain results. A straightforward and effective selection strategy for parameters of the exponential function is also provided, enabling the EFWA method to achieve self-adaptive post-processing.</p><h3>Results</h3><p>The calculation examples of synthetic images indicate that, the proposed EFWA method can consistently yield high measurement accuracy for unidirectional and multi-directional complex deformation fields and exhibits superior spatial resolution compared to the PLS method. The minimum Metrological Efficiency Indicator (MEI) value for the EFWA method is 1.72, compared to 4.67 for original results and 5.10 for the PLS method. The results of a tensile experiment carried out on an open-hole specimen indicate that, after the EFWA method is implemented, the strain results in areas away from the hole are effectively smoothed and the strain results in areas around the hole are preserved.</p><h3>Conclusions</h3><p>The proposed EFWA method can achieve effective and easy-to-implement strain measurement for full-gradient strain fields.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 2","pages":"177 - 194"},"PeriodicalIF":2.0,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143513150","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":"Characterization of Environmental Stress Cracking in Polymers Through a Modified Bent Strip Test Method","authors":"Y. Zhang,&nbsp;L. Wu,&nbsp;B. Jar,&nbsp;X. Xing","doi":"10.1007/s11340-024-01129-y","DOIUrl":"10.1007/s11340-024-01129-y","url":null,"abstract":"<div><h3>Background</h3><p>The environmental stress cracking resistance (ESCR) of polymers is characterized most conveniently by the bent strip method standardized as ASTM D1693. The method has, however, suffered from poor reproducibility of the ESCR results.</p><h3>Objective</h3><p>In this study we propose modifications on the standardized method to reduce the variability of the ESCR results.</p><h3>Methods</h3><p>The notch is introduced to the specimens with the aid of automate testing machine instead of manual notching. The proposed method is then applied for a systematic investigation on the influence notch offset distance, notch inclination angle, notch depth on the environmental stress cracking behavior of polyethylene material.</p><h3>Results</h3><p>The results reveal interesting phenomenon that crack initiation occurs at the interior point between the endpoint and the middle of the notch, instead of at the middle point of the notch, where the maximum stress or strain is located. Finite element simulation has been conducted to elucidate root cause of this phenomenon. It has been found that the crack initiates at a point that is very close to the position of the maximum stress triaxiality, although the crack initiation position shifts slightly toward the position of the maximum stress or strain.</p><h3>Conclusions</h3><p>As a result, the crack initiation is controlled by the stress, strain and stress triaxiality, but stress triaxiality plays a dominant role in the initiation of environmental stress cracking.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"157 - 173"},"PeriodicalIF":2.0,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994697","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":"Evolving Properties of Biological Materials Captured via Needle-Based Cavity Expansion Method","authors":"H. M. Varner,&nbsp;S. K. Naghibzadeh,&nbsp;K. C. Spaeth,&nbsp;A. Klein,&nbsp;T. Cohen","doi":"10.1007/s11340-024-01128-z","DOIUrl":"10.1007/s11340-024-01128-z","url":null,"abstract":"<div><h3>Background</h3><p>The mechanical properties of biological tissues change over time and with disease progression. Quantifying these mechanical properties can thus be instrumental for medical diagnosis and for evaluation of tissue viability for transplant. However, soft and biological materials are exceptionally challenging to mechanically characterize using conventional testing methods, which are hindered by limitations of sample size, fixturing capabilities, and sample preparation.</p><h3>Objective</h3><p>We hypothesize that Volume Controlled Cavity Expansion (VCCE) is well-suited to capture subtle mechanical differences in biological tissue. The objective of this work is therefore twofold: first, we seek to quantify how stiffness of liver and gelatin evolve with age. In achieving this understanding, we aim to demonstrate the precision of VCCE in measuring subtle changes in the mechanical properties of biological tissues.</p><h3>Methods</h3><p>Performing VCCE tests over 15 days in samples of gelatin and liver (porcine and bovine), we track the evolving pressure-volume response and deformation limits of the materials.</p><h3>Results</h3><p>In both materials, we observed time-dependent variation of the stiffness and fracture thresholds. In gelatin VCCE repeatably captured stiffening over time, which was correlated with a higher fracture stress. This was in contrast to observations in bovine liver, where stiffening corresponded to a lower fracture stress. Porcine liver initially stiffened, then reversed this trend and relaxed.</p><h3>Conclusion</h3><p>Through this work we show that liver and gelatin stiffen with age, and that this trend is measurable via VCCE. These results highlight the utility of VCCE and call attention to the need for a new class of mechanism based constitutive models that are capable of capturing variations in material over time with a minimal number of parameters.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"141 - 155"},"PeriodicalIF":2.0,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994559","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":"Study of Thermomechanical Behavior of Refractory Materials Under Thermal Gradient. Part I – Presentation of ATHORNA Device and Experimental Protocol","authors":"R. Kaczmarek,&nbsp;R. De Oliveira,&nbsp;Y. Lalau,&nbsp;G. Oum,&nbsp;I. Khlifi,&nbsp;J.-C. Dupré,&nbsp;P. Doumalin,&nbsp;O. Pop,&nbsp;N. Tessier-Doyen,&nbsp;M. Huger","doi":"10.1007/s11340-024-01126-1","DOIUrl":"10.1007/s11340-024-01126-1","url":null,"abstract":"<div><h3>Background</h3><p>Improving the understanding of how a refractory material responds to thermal shocks and allowing the validation of finite element models require a valuable tool for experimental data collection.</p><h3>Objective</h3><p>This paper introduces an innovative, sophisticated, and highly reliable experimental device designed to apply a controlled cyclic thermal gradient in a disk-shaped ceramic refractory sample and to simultaneously monitor thermomechanical response and potential damage.</p><h3>Methods</h3><p>This device, named Advanced measurements for in-situ Thermomechanical monitORing of large sample uNder thermal grAdient, is based on a CO₂ laser beam to generate a calibrated thermal flux sequence at the top face while accurately measuring temperature field at the bottom face by an infrared camera. The displacement field of the bottom face is also continuously monitored by a stereo-vision system, enabling a precise measurement of 3D displacements and, thus, of the local strains. An accurate monitoring of the crack extension is performed thanks to the Two-Part Digital Image Correlation technique.</p><h3>Results</h3><p>Throughout the thermal cycling sequence applied to an exemplar sample, the device has proved to be a robust and reliable system able to provide very accurate experiment data in terms of displacement, strain, temperature fields and crack length/opening.</p><h3>Conclusions</h3><p>This device represents a significant advancement in in-situ monitoring of a refractory sample and contributes to the comprehensive characterization of materials under thermal gradients. More investigations and comparison with thermomechanical Finite Element modelling are shown in a second part of this paper.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"123 - 140"},"PeriodicalIF":2.0,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994756","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":"An Attempt to Predict Transparent Armor Ballistic Performance through Quasi-Static Punch Shear Test","authors":"A.A. Bautista Villamil,&nbsp;A. Maranon,&nbsp;J.P. Casas-Rodriguez,&nbsp;T. Benitez,&nbsp;E. Pavolini","doi":"10.1007/s11340-024-01123-4","DOIUrl":"10.1007/s11340-024-01123-4","url":null,"abstract":"<div><h3>Background</h3><p>Transparent armor systems are traditionally designed following a trial-and-error approach, which involves high development costs associated with ballistic testing. This research article presents a novel methodology, termed quasi-static multi-punch shear testing, within the domain of transparent armor systems.</p><h3>Objective</h3><p>The primary aim is to establish a correlation between multi-hit ballistic tests at Level III-A according to the NIJ 0108.01 standard, achieved through an adaptation of the single-shot ballistic limit methodology, and the quasi-static multi-punch shear testing. The objective is to utilize a simple experimental methodology that provides insights into the multi-hit ballistic behavior of transparent armors.</p><h3>Methods</h3><p>Parameters such as absorbed energy and observed damage mechanisms were utilized to assess the potential relationship between these tests. Transparent armor samples that underwent testing using the quasi-static multi-punch shear test were subsequently cross-sectioned using a water jet cutting machine to facilitate visualization of material damage. In addition, drawing on insights from quasi-static multi-punch shear testing results, the K-means clustering algorithm was employed to predict the likelihood of a specific transparent armor system passing a multi-hit ballistic test.</p><h3>Results</h3><p>Various damage mechanisms were observed as a function of the punch displacement, and correlations were made with the load–displacement curves. Furthermore, the implementation of the K-means clustering algorithm successfully classified transparent armor into two groups: those that passed the ballistic test and those that did not.</p><h3>Conclusions</h3><p>This research significantly advances understanding of transparent armor system behavior under multi-hit conditions and offers a promising predictive tool for evaluating their performance through straightforward and cost-effective experimentation.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"107 - 122"},"PeriodicalIF":2.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01123-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994351","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}