Experimental Mechanics最新文献

{"title":"On the Cover: Plasticity Bridges Microscale Martensitic Shear Bands in Superelastic Nitinol","authors":"","doi":"10.1007/s11340-025-01188-9","DOIUrl":"10.1007/s11340-025-01188-9","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 5","pages":"603 - 603"},"PeriodicalIF":2.0,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144074204","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":"Collapse Behavior of Cylindrical Shells with Anticlastic Curvature Sections","authors":"A. Pandey,&nbsp;D. Fontaine,&nbsp;A. Shukla","doi":"10.1007/s11340-025-01186-x","DOIUrl":"10.1007/s11340-025-01186-x","url":null,"abstract":"<div><h3>Background</h3><p>Understanding the dynamic buckling behavior of cylindrical shells is crucial for various marine engineering applications including underwater pipelines, yet the influence of concave circumferential grooves on their collapse capacity remains underexplored.</p><h3>Objective</h3><p>This study aims to investigate the effect of groove geometry on the dynamic buckling behavior of aluminum tubes under hydrostatic pressure.</p><h3>Methods</h3><p>Experiments were conducted in a water-filled pressure vessel facility, utilizing high-speed imaging with 3D Digital Image Correlation and piezoelectric transducers to capture transient collapse behavior of cylindrical shells and associated local pressure histories. Finite element simulations complemented the experiments to analyze critical pressure sensitivity to groove wall thickness.</p><h3>Results</h3><p>The presence of a mid-length groove increased collapse capacity by 25% to 50% compared to non-grooved tubes and reduced peak dynamic overpressure. Groove depth significantly influenced failure mode: deeper grooves induced local buckling, while shallow grooves led to global collapse. Simulations further demonstrated collapse capacity improvements reaching up to 65% for tubes with a groove.</p><h3>Conclusions</h3><p>Introducing a concave circumferential groove enhances the collapse resistance of cylindrical shells, with geometric configuration playing a pivotal role in determining failure mode.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"66 1","pages":"87 - 101"},"PeriodicalIF":2.4,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-025-01186-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146049358","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":"Improving Reversed Three-Point Bending Tests for Characterising the Fatigue Life of Polymers","authors":"S. Baril-Gosselin","doi":"10.1007/s11340-025-01184-z","DOIUrl":"10.1007/s11340-025-01184-z","url":null,"abstract":"<div><h3>Background</h3><p>Cyclic loading is a leading cause of material failure and accurate testing methods are required to predict the life of components.</p><h3>Objective</h3><p>This work investigated the challenges of performing reversed three-point bending experiments for characterising the fatigue life of polymers and composites, and sought to develop guidelines for improving the testing method.</p><h3>Methods</h3><p>Testing was performed with polypropylene (PP) and glass-fibre reinforced PP on a test fixture that featured double-sided supports. Monotonic and fully reversed (i.e. stress ratio <i>R</i> = - 1) cyclic bending experiments were conducted to characterise the effects that the test conditions, including the type of supports and level of contact between the specimens and anvils, have on the measurements.</p><h3>Results</h3><p>Stresses generated during reversed bending are highly dependent on the type of fixture configuration used. Most configurations that were tested led to mechanical interlocking that altered the bending moments and generated membrane stresses. In this work, the purest form of reversed bending was achieved using double-sided pivoting supports, and a 0.35 mm gap between specimens and anvils to allow sliding in the supports.</p><h3>Conclusions</h3><p>This configuration provided the most similar stress state to that obtained from the standardised simply-supported beam experiments that are used for characterising the quasi-static flexural properties of materials, and was ultimately the configuration that provided the most reliable fatigue data.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 6","pages":"969 - 980"},"PeriodicalIF":2.4,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-025-01184-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145168701","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":"Mechanical Characterization of Additive-Manufactured Ti-6Al-4V Processed via Bound Metal Deposition","authors":"E. Devine,&nbsp;M. Lester,&nbsp;T. McElroy,&nbsp;T. Valenzuela,&nbsp;W. LePage","doi":"10.1007/s11340-025-01178-x","DOIUrl":"10.1007/s11340-025-01178-x","url":null,"abstract":"<div><h3>Background</h3><p>Additive manufacturing (AM) is rapidly growing, with new AM methods continually in development. Alloys processed with novel methods require systematic characterization to understand and validate the materials, especially for demanding fields.</p><h3>Objective</h3><p>This study characterized the mechanical properties and failure mechanisms of a Ti-6Al-4V alloy manufactured with bound metal deposition (BMD), a form of metal extrusion (MEX) AM.</p><h3>Methods</h3><p>Specimens made of Ti64 were printed via Desktop Metal’s Studio System 2 through a printing, debinding, and sintering process. The microstructure was analyzed with optical metallography and a newly developed open-source porosity analysis tool. Scanning electron microscopy (SEM), optical microscopy, and compositional analysis of green, brown, and sintered parts were conducted to study the material and its failure modes. Sintered specimens were tensile and hardness tested.</p><h3>Results</h3><p>As-sintered specimens exhibited ductility more than 10 times lower than wrought Ti64, partially due to contamination/impurity that formed brittle <span>(alpha )</span>-case titanium. Sources of contamination may have included the sacrificial Al<span>(_2)</span>O<span>(_3)</span> interlayer, the wax/polymer binder, and/or impurity introduction from the furnace. Fractography imaging found quasi-cleavage fracture initiating at areas of high surface roughness along the ceramic interlayer surface of the parts and transitioning into dimple rupture and intergranular decohesion.</p><h3>Conclusions</h3><p>Elevated contamination levels, high surface roughness, and internal porosity led to low elongation and ultimate strength in the Ti64 BMD alloy. With the processing route presented here, BMD for Ti64 may not be suitable for applications that demand high ductility and strength with minimal impurities, although with process refinement, the method may be promising for certain applications</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 4","pages":"573 - 596"},"PeriodicalIF":2.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919006","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":"Mechanics of Additively Manufactured Materials","authors":"L.R. Xu,&nbsp;G. J. Pataky","doi":"10.1007/s11340-025-01181-2","DOIUrl":"10.1007/s11340-025-01181-2","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 4","pages":"423 - 425"},"PeriodicalIF":2.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919005","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":"4D Porosity Evolution in Additively Manufactured 316L Stainless Steel through In-Situ Tensile Testing and X-Ray Computed Tomography","authors":"D. Hertz-Eichenrode,&nbsp;H. Talebinezhad,&nbsp;A. Shmatok,&nbsp;R.D. Fischer,&nbsp;S. Bremen,&nbsp;W. Reichert,&nbsp;B.C. Prorok","doi":"10.1007/s11340-025-01180-3","DOIUrl":"10.1007/s11340-025-01180-3","url":null,"abstract":"<div><h3>Background</h3><p>Many aspects of ductile failure through microvoid coalescence remain elusive due to the challenging spatial and temporal scales it operates on. Experimentally resolving all aspects of the process remains a significant goal of researchers. Much of the current understanding has been derived from post-mortem metallography, leaving key aspects of its evolution undocumented.</p><h3>Objective</h3><p>This work builds on efforts using X-ray computed tomography (XCT) characterize voids and their evolution under loading.</p><h3>Methods</h3><p>It employs <i>in-situ</i> XCT tensile testing on 316L Stainless Steel samples that were constructed by laser powder bed fusion that contain tailored, pre-existing voids with a spatial scale relevant to the growth and evolution stages of microvoid coalescence. Pre-existing voids extended the observation window for monitoring void growth and interaction under loading. They also enhanced fiducial correlation of voids during deformation.</p><h3>Results</h3><p>Void populations were found to increase under loading as their deformed dimensions rendered them detectable by the XCT algorithm. Neighboring voids underwent interconnection events by a cleavage process when stress concentrations between them exceeded the macroscopic yield stress. Pores that did not undergo interconnection events were found to revert to their initial size and population after unloading. Finally, the porosity structure before failure was correlated to features on the fracture surface with high fidelity.</p><h3>Conclusions</h3><p>This unique combination of <i>in-situ</i> XCT tensile testing on samples with tailored void structure enabled new visualization and quantification of void evolution under load as well as strong correlation to the observed stress–strain behavior and post-mortem fracture characteristics.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 4","pages":"553 - 572"},"PeriodicalIF":2.0,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-025-01180-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919139","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":"Estimation of Elastic Modulus with Multiple Indenters","authors":"Y. Yoon,&nbsp;G. Han,&nbsp;N. Kim,&nbsp;H. Lee","doi":"10.1007/s11340-025-01173-2","DOIUrl":"10.1007/s11340-025-01173-2","url":null,"abstract":"<p>The conventional Oliver-Pharr method of estimating elastic modulus shows reasonably good accuracy, but errors occur due to inaccuracies in the actual contact area.</p><p>To resolve this issue, this study proposed a new method to estimate the elastic modulus using two different indenters without additional equipment or complicated calibration. We aimed to estimate the elastic modulus using the theoretical indentation depth, without the consideration of sink-in <b>/</b> pile-up effect.</p><p>A numerical indentation test was performed using Berkovich and spherical indenters, and the theoretical contact area and initial unloading slope of the indentation load-depth curve were calculated to derive <i>c</i>-ratio based on the correction factor <i>c</i>. Numerical validation using finite element analysis for various material properties of <i>J</i>_<i>2</i> and pressure-dependent hardening models showed that the method estimates the elastic modulus with <i>R</i> ² = 98 %, outperforming the conventional method.</p><p>Microindentation tests were conducted on copper, Al1050, SS304 specimens for experimental validation. The estimated elastic moduli with proposed method showed good agreement with those from tensile tests with an error of 7 %.</p><p>This study proposed a new method for estimating elastic modulus that overcomes the limitations of the conventional method, which is difficult to accurately measure the actual contact area at maximum load, and has high applicability to various materials by using the correction factor <i>c</i>.</p>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 6","pages":"943 - 953"},"PeriodicalIF":2.4,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145164708","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":"A Robust Deep Learning-Assisted Digital Image Correlation for Deformation Measurement at 1600 °C in Air","authors":"G. Niu,&nbsp;R. Zhu,&nbsp;Z. Qu,&nbsp;H. Lei,&nbsp;P. Wang,&nbsp;H. Yang,&nbsp;D. Fang","doi":"10.1007/s11340-025-01182-1","DOIUrl":"10.1007/s11340-025-01182-1","url":null,"abstract":"<p>Digital image correlation (DIC) is an image-based deformation measurement method. However, problems such as heat haze, speckle oxidation and debonding, and image overexposure in ultra-high-temperature environments lead to image degradation and compromise the reliability of deformation measurement.</p><p>This study proposes a robust and high-precision DIC algorithm designed to measure deformation stably from low-quality speckle images by leveraging machine learning. An ultra-high-temperature <i>in-situ</i> X-ray imaging device addresses challenges like speckle instability and heat haze interference. The proposed algorithm and experimental device are combined to measure the deformation field at 1600 °C in air.</p><p>A novel image matching network-assisted digital image correlation (IMN-DIC) is proposed. This approach uses a deep learning-based image matching network to extract and match features for initial displacement estimation. Subsequently, an iterative algorithm based on the inverse compositional Gauss–Newton (IC-GN) method is applied to achieve sub-pixel accuracy in high-temperature deformation field measurements. Numerical experiments and real experiments of C/SiC composite samples under tension at 1600 °C in the air with optical and X-ray imaging were carried out to verify the effectiveness of the IMN-DIC.</p><p>For high-quality optical speckle images, IMN-DIC achieved comparable measurement accuracy but with greater computational efficiency than previous feature-based DIC methods. In X-ray images captured at 1600 °C in air, the traditional DIC method successfully processed only 50.17% of points of interest (POIs), whereas IMN-DIC achieved 98.96%, demonstrating superior robustness.</p><p>The IMN-DIC method exhibits high robustness, reliably capturing deformation data from low-quality speckle images with weak textures and high noise levels. This approach holds significant promise for applications in extreme environments where artificial speckle generation is challenging and image quality is compromised.</p>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 6","pages":"955 - 968"},"PeriodicalIF":2.4,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145164707","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":"Evaluation of an Improved Filtering Method for Strain Measurement at High Temperatures Using 2D-DIC","authors":"L. P. Luong,&nbsp;G. Alonso Aruffo,&nbsp;R. Bonnaire,&nbsp;L. Penazzi","doi":"10.1007/s11340-025-01174-1","DOIUrl":"10.1007/s11340-025-01174-1","url":null,"abstract":"<div><h3>Background</h3><p>The Two-Dimensional Digital Image Correlation (2D-DIC) method is widely used as a non-contact full-field kinematic measurement, but it presents significant errors related to temperature effects including the image con- trast and heat waves. Consequently, results of mechanical displacement or strain measured by the 2D-DIC method, especially strains in the elastic domain of materials, is significantly dispersed.</p><h3>Objective</h3><p>The aim of this study is to propose a very simple 2D-DIC method, using commercial DIC software with no need of additional storage to accurately measure strain and displacements at high temperatures, typically at the hot metal forming temperatures, from 400 ^<i>◦</i>C to 750 ^<i>◦</i>C.</p><h3>Methods</h3><p>This study demonstrates the influence of temperature effects (radiation and heat waves) on strain measurements obtained with the 2D-DIC method in the elastic regime (ε &lt; 0.05) of the TA6V titanium alloy material at high temperatures. Furthermore, the strain measurement errors at different temperatures were characterized by the Background Oriented Schlieren technique (BOS). Correction methods using temperature-dependent low-pass filters for strain measurement errors are suggested.</p><h3>Results</h3><p>The correction methods allow separating mechanical strain fields and strain measurement errors caused by temperature effects. The efficiency of the correction methods is demonstrated by identifying the Young’s modulus (E) and the Thermal Expansion Coefficient (TEC) of the TA6V. After corrections, E and the TEC of the TA6V are close to the reference values found in the literature. Conclusion: The coefficient <i>R</i>² from the linear regression method to determine the Young’s modulus from tensile test at 600 ^<i>◦</i>C increases from 0.783 to 0.989, revealing the great potential of using the improved-2D-DIC method for full-field kinematic measurements of mechanical tests at high temperatures.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 6","pages":"927 - 941"},"PeriodicalIF":2.4,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145164083","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":"A Strain Field Reconstruction Method Based on Digital Twin by Multi-Level Fusion of Multi-Type Data","authors":"B. Wang,&nbsp;X. Ke,&nbsp;J. Wang,&nbsp;K. Liu,&nbsp;Z. Song,&nbsp;J. Zhou,&nbsp;C. Zhou","doi":"10.1007/s11340-025-01183-0","DOIUrl":"10.1007/s11340-025-01183-0","url":null,"abstract":"<div><h3>Background</h3><p>Finite element analysis (FEA), digital image correlation (DIC), and strain gauge are usually used for test monitoring. Reconstructed by FEA strain field and strain gauges, the fusion field (DT-SFRM) has higher accuracy than FEA, and DT-SFRM accuracy is acceptable for small structural deformation. However, large deformation of thin-walled structures is accompanied by complex strain field, and the difference in strain distribution between FEA and strain gauges data increases sharply. The low-accuracy FEA strain field and small amount of strain gauges lead to insufficient accuracy of DT-SFRM.</p><h3>Objective</h3><p>This study aims to construct a high-accuracy strain field for test monitoring.</p><h3>Methods</h3><p>A strain field reconstruction method based on digital twin (DT) by multi-level fusion of multi-type data (DT-MFMD) is proposed. Large number of relatively high-accuracy DIC data is used to improve global FEA strain field accuracy. The high-accuracy strain gauges are used to further improve fusion field accuracy of FEA and DIC. A tensile test of large opening plate shell (LOPS) is performed to verify the advantage of DT-MFMD.</p><h3>Results</h3><p>The AvgErr (6.6%) and MaxErr (23.5%) of DT-MFMD are 16.0% and 58.8% lower than those of DT-SFRM, and the DT-MFMD is less affected by large deformation. In addition, the strain gauges number of DT-MFMD reduces by more than 62.5% under the same accuracy goal compared with that of DT-SFRM.</p><h3>Conclusions</h3><p>The DT-MFMD is validated to have a better application prospect for large deformation and complex strain field distribution.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 6","pages":"907 - 925"},"PeriodicalIF":2.4,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145163772","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}