Experimental Mechanics最新文献

{"title":"A Note of Gratitude from the Editor-in-Chief","authors":"A. Zehnder","doi":"10.1007/s11340-024-01121-6","DOIUrl":"10.1007/s11340-024-01121-6","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1383 - 1383"},"PeriodicalIF":2.0,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443228","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: Accounting for Localized Deformation: A Simple Computation of True Stress in Micropillar Compression Experiments","authors":"","doi":"10.1007/s11340-024-01120-7","DOIUrl":"10.1007/s11340-024-01120-7","url":null,"abstract":"","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1381 - 1381"},"PeriodicalIF":2.0,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443227","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":"Dynamic Magneto-Mechanical Analysis of Isotropic and Anisotropic Magneto-Active Elastomers","authors":"C.D. Pierce,&nbsp;N.J. Salim,&nbsp;K.H. Matlack","doi":"10.1007/s11340-024-01115-4","DOIUrl":"10.1007/s11340-024-01115-4","url":null,"abstract":"<div><h3>Background</h3><p>Magneto-active elastomers (MAEs) are soft composite materials comprising ferromagnetic particles in an elastomer matrix which exhibit a magnetically-induced effective modulus change. The change in modulus has been experimentally studied in many MAE formulations using several techniques; however, this makes comparisons between studies difficult, and there lacks a comprehensive study on the dynamic magneto-mechanical properties of MAEs.</p><h3>Objective</h3><p>In this article, we seek to understand the effect of mechanical loading direction and magnetic field orientation on the dynamic magneto-mechanical response of isotropic and anisotropic MAEs.</p><h3>Methods</h3><p>We develop a new apparatus to perform dynamic mechanical analysis of MAEs at frequencies up to 600Hz subject to magnetic fields of varying strength. We measure the magnetically-induced modulus change in MAEs prepared from a single elastomer-particle combination and specimen geometry, systematically varying the anisotropy direction relative to the magnetic field.</p><h3>Results</h3><p>Our results show that isotropic MAEs are up to three times stiffer and anisotropic MAEs up to 65 times stiffer than pure elastomer. Of all configurations studied, the longitudinal modulus of anisotropic MAEs exhibits the largest absolute magnetically-induced change while the transverse modulus exhibits the largest relative change. The magnetically-induced change in loss factor depends on anisotropy and loading condition: isotropic MAEs have no change in loss factor while anisotropic MAEs become less lossy at low strain amplitudes but more lossy at high strain amplitudes.</p><h3>Conclusions</h3><p>These results provide new insights into the fundamental mechanisms by which microstructure and magnetic field interact to affect the MAE effective properties.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1601 - 1618"},"PeriodicalIF":2.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443266","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":"Measurement of the Tension Loss in a Cable Traveling Over a Pulley, for Low-Speed Applications","authors":"P. Máté,&nbsp;A. Szekrényes","doi":"10.1007/s11340-024-01097-3","DOIUrl":"10.1007/s11340-024-01097-3","url":null,"abstract":"<div><h3>Background</h3><p>Wire ropes or cables are widely used solutions for force transmission in several industrial applications. Their hysteretic behavior may significantly influence control accuracy or the force transmission’s efficiency. Cables traveling through sheaves can suffer a relatively high tension loss, which this article addresses.</p><h3>Objective</h3><p>This paper aims to present a simple measurement method for the tension loss in cables traveling over sheaves on bearings.</p><h3>Methods</h3><p>The presented measurement method uses a cable-pulley system with a spring installed at one cable end. The pulley is moved in a zig-zag pattern. The force is measured on both cable ends; this way, the tension loss can be determined as a function of the cable tension. The force was measured with S-type load cells, which are highly sensitive to off-axis loads; this problem can be overcome by proving that the force measurement has a proportional error, which can be eliminated from the frictional coefficient. The measurements are compared to two models from the literature; one approximates the power loss of a cable drive by calculating the work of the cable’s inner friction, and the other is a cable bending model, which is used to determine the hysteretic energy of the cyclic bending.</p><h3>Results</h3><p>The result of the measurement evaluation is a coefficient of tension loss that contains the loss coming from the cable bending and the bearing friction. Four cable types and a steel strip with negligible bending hysteresis were measured, the latter for control measurement. It is demonstrated that a significant part of the tension loss originates from the inner friction of the cable and that it is equal to the hysteretic energy of the cyclic bending.</p><h3>Conclusion</h3><p>The presented method provides a robust measurement for the tension loss factor in cables traveling over pulleys. It is proven that the off-axis loads cause a proportional error in the force measured by S-type load cells, and this measurement error can be eliminated from the tension loss factor. The results demonstrated that the presented models can be used to predict the tension loss in cables traveling over sheaves.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1579 - 1599"},"PeriodicalIF":2.0,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01097-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443261","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":"Biomechanical Hand Model: Modeling and Simulating the Lateral Pinch Movement","authors":"A.F. Lemos,&nbsp;L. A. Rodrigues da Silva,&nbsp;B. V. Nagy,&nbsp;P. N. Barroso,&nbsp;C. B. S. Vimieiro","doi":"10.1007/s11340-024-01109-2","DOIUrl":"10.1007/s11340-024-01109-2","url":null,"abstract":"<div><h3>Background</h3><p>Hand movements are crucial in daily activities, sparking extensive interest and research in biomechanical models. While existing models offer valuable insights, their complexity and processing costs may limit their suitability for all applications, sometimes impeding research efficiency.</p><h3>Objectives</h3><p>This study aimed to develop a biomechanical model of the human hand for analyzing the physiology of lateral pinch movement. Unlike conventional methodologies, this approach focuses on delivering a computationally efficient model while incorporating the trapeziometacarpal joint into the analysis.</p><h3>Methods</h3><p>The model, which operates in a multibody environment, simulates lateral pinching movement by applying external time-varying torques to digit joints, emulating musculature, tendons, and ligaments. Torque estimation was achieved through the Euler-Lagrange approach. The model generates animated representations of the movement, aiding pathology identification and outputting dynamic variables. The model’s was validated through data acquired from asymptomatic subjects via an OptiTrack system.</p><h3>Results</h3><p>The average disparity between the expected and obtained joint angular displacements was <span>(varvec{6.06~%})</span> and <span>(varvec{1.90~%})</span> during validation and verification stages, suggesting high fidelity in the model performance. Correlation analysis revealed strong positive linear relationships and robust correlations between the obtained and expected configuration data. Model-generated pinch postures closely resembled expected physiological patterns, with results falling within the range for asymptomatic individuals documented in the scientific literature.</p><h3>Conclusion</h3><p>The system efficiently analyzes dynamic variables at a low computational cost, offering animated representations for pathology identification. The model’s potential for rehabilitation solutions and adaptability, coupled with its accuracy and versatility, make it an asset for advancing hand biomechanics research.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1557 - 1578"},"PeriodicalIF":2.0,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01109-2.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142443235","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":"Size Effects in Strength and Strain Hardening Behavior of Single-Crystal 7075 Aluminum Alloy Micropillars","authors":"H. Li,&nbsp;D. Zhao,&nbsp;Y. Cui,&nbsp;C. Dan,&nbsp;S. Ma,&nbsp;L. Wang,&nbsp;J. Liu,&nbsp;Y. Li,&nbsp;Z. Chen,&nbsp;H. Wang","doi":"10.1007/s11340-024-01112-7","DOIUrl":"10.1007/s11340-024-01112-7","url":null,"abstract":"<div><h3>Background</h3><p>The size effect and deformation instability exhibited by materials at the micro- and nano-scale constrain the development and application of miniaturized devices. Introducing different defects in materials through different technical means to improve the deformation stability of materials has been the main research point of micro- and nano mechanics.</p><h3>Objective</h3><p>This paper presents a novel strategy to completely eliminate the instability of microscopic deformations by the introduction of high-density precipitates in aluminum alloys by means of suitable heat treatment.</p><h3>Methods</h3><p>A suitable heat treatment is used to introduce a high density of precipitates in the 7075 aluminum alloy. Using the Focused Ion Beam technique and in situ micropillar compression tests, micron-sized single-crystal micropillars were fabricated and the size dependence of the strength and strain-hardening behavior of 7075 aluminum alloy was systematically analyzed.</p><h3>Results</h3><p>Compared with precipitate-free Al–Mg alloy micropillars, the micropillars fabricated from 7075 aluminum alloy exhibited more stable deformation behavior, predominantly due to the impediment of dislocation motion by precipitates. The power-law exponent for yield strength relative to pillar size was determined to approach a near-zero value, indicating a negligible dependency of yield strength on specimen size. Similarly, the smaller the size of micropillar, the higher the hardening rate, which can be rationalized by exhaustion hardening.</p><h3>Conclusions</h3><p>The proposed method can eliminate the size effect of materials with pillar size above 0.5 μm and leads to a stabilization in deformation behavior. These are advantageous for the application of micro- and nano-sized components in advanced engineering systems.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1545 - 1555"},"PeriodicalIF":2.0,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260938","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":"Validation of Hole-Drilling Residual Stress Measurements in Workpieces of Various Thickness","authors":"M. C. Lakey,&nbsp;M. R. Hill","doi":"10.1007/s11340-024-01107-4","DOIUrl":"10.1007/s11340-024-01107-4","url":null,"abstract":"<div><h3>Background</h3><p>A recent revision to the ASTM E837 standard for near-surface residual stress measurement by the hole-drilling method describes a new thickness-dependent stress calculation procedure applicable to “thin” and “intermediate” workpieces for which strain versus depth response depends on workpiece thickness. This new calculation procedure differs from that of the prior standard, which applies only to thick workpieces with strain versus depth response independent of thickness.</p><h3>Objective</h3><p>Herein we assess the new calculation procedures by performing hole-drilling residual stress measurements in samples with a range of thickness.</p><h3>Methods</h3><p>Near-surface residual stress is measured in a thick aluminum plate containing near-surface residual stress from a uniform shot peening treatment, and in samples of different thickness removed from the plate at the peened surface. A finite element (FE) model is used to assess consistency between measured residual stress across the range of sample thickness.</p><h3>Results</h3><p>Measured residual stress varies with sample thickness, with thinner samples exhibiting smaller near-surface compressive stress and a larger gradient of subsurface stress. These trends are consistent with both observed bending (curvature) of the removed samples and the trend in FE-calculated expected residual stress. The measured and expected residual stresses are in good agreement for samples of intermediate thickness, but the agreement decreases with sample thickness. Measured residual stress is invariant with gage circle diameter.</p><h3>Conclusion</h3><p>The new thickness-dependent stress calculation procedure for hole-drilling provides meaningful improvement compared to thick-workpiece calculations.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1529 - 1544"},"PeriodicalIF":2.0,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01107-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260886","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":"Simultaneous Measurement of Fiber-Matrix Interface Debonding and Tunneling Using a Dual-Vision Experimental Setup","authors":"K. Z. Uddin,&nbsp;H. Girard,&nbsp;N. B. Mennie,&nbsp;A. Doitrand,&nbsp;B. Koohbor","doi":"10.1007/s11340-024-01111-8","DOIUrl":"10.1007/s11340-024-01111-8","url":null,"abstract":"<div><h3>Background</h3><p>Fiber-matrix debonding is a precursor for transverse cracking and several other types of damage in fiber composites. However, to date, there are limited experiment-based reports that study the fundamental mechanisms of fiber-matrix debonding.</p><h3>Objective</h3><p>This work aims to uncover the governing mechanisms of fiber-matrix interface debonding by full-field measurements supplemented by numerical simulations. In particular, the application of a dual-vision image-based characterization approach on single glass macro fiber samples is discussed and proven useful in understanding the in-plane and out-of-plane debonding characteristics at the fiber-matrix interface.</p><h3>Methods</h3><p>Full-field strain and displacement measurements based on digital image correlation are performed on model single-fiber composites. The use of a dual-vision system allows strain measurements in the vicinity of the fiber-matrix interface, also allowing for the identification of critical strain and stress values corresponding to the initiation and propagation of debonding damage. The experimental data are used to calibrate an inverse identification approach that outputs the shape of the debonded interface along the fiber length.</p><h3>Results</h3><p>Full-field measurements allow for establishing correlations between local and global strain fields. Observation of debonding propagation along the fiber axis seems to be representative of the crack tunneling during the early stages of the failure process, i.e., when the crack tip is subjected to opening mode only.</p><h3>Conclusions</h3><p>Side view measurements are useful as a first-order approximation of the debonding propagation velocity along the fiber axis but fail to provide accurate measurements for the debonding shape, esp. in areas where the crack is under a dominantly shear stress state. This issue can be resolved by full-field measurements coupled with computational simulations.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1497 - 1511"},"PeriodicalIF":2.0,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01111-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260887","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":"An Accurate Strain Gauge Positioning Approach Based on Geometry and Color Features","authors":"C. Zhou,&nbsp;H. Sun,&nbsp;Y. Li,&nbsp;Z. Song,&nbsp;X. Bi,&nbsp;B. Wang","doi":"10.1007/s11340-024-01114-5","DOIUrl":"10.1007/s11340-024-01114-5","url":null,"abstract":"<div><h3>Background</h3><p>Strain gauges commonly used in structural testing are manually pasted, usually with a 1–4 mm deviation between the actual pasted position and the theoretical position. The deviation leads to measurement errors, which are more pronounced in high strain gradient regions with stiffness discontinuities such as openings, reinforcements, and notches.</p><h3>Objective</h3><p>This study aims to obtain the actual pasted position of strain gauges and thus improving the testing measurement accuracy.</p><h3>Methods</h3><p>A non-contact strain gauge positioning method is proposed. Firstly, considering that the strain gauges have a regular shape, the irregular borderlines are filtered out based on the geometric features of a borderline image. Secondly, considering that the color of the strain gauge is significantly different from the test piece, and the color features within the borderline are extracted by clustering and compared with the strain gauges to complete the recognition. Finally, based on the epipolar geometry, the matching relationship of the strain gauges in different images is obtained, and the positioning is completed based on binocular vision according to the strain gauge recognition results.</p><h3>Results</h3><p>For a simple plate, the average positional error of strain gauges is reduced by 71%. For a small square tube, the average error is reduced by 44%. For a large cylinder, the average error is reduced by 32.4%.</p><h3>Conclusion</h3><p>The proposed non-contact strain gauge positioning method can obtain high precision strain gauge positions, which effectively improves the test measurement accuracy.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1513 - 1527"},"PeriodicalIF":2.0,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189298","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":"Size Effect on the Ductile Fracture of the Aluminium Alloy 2024-T351","authors":"F. Šebek,&nbsp;P. Salvet,&nbsp;P. Boháč,&nbsp;R. Adámek,&nbsp;S. Věchet,&nbsp;T. Návrat,&nbsp;J. Zapletal,&nbsp;M. Ganjiani","doi":"10.1007/s11340-024-01108-3","DOIUrl":"10.1007/s11340-024-01108-3","url":null,"abstract":"<div><h3>Background</h3><p>Reliably calibrated criteria are needed for an accurate prediction of fracture of various components. However, there is not always a sufficient amount of material available. Therefore, miniature testing provides an alternative that is researched together with the following calibration of the ductile fracture criteria and investigating the size effect.</p><h3>Objective</h3><p>The aim is to design miniature testing equipment and specimens for tensile testing, which covers various stress states. This is supplemented by the small punch test, which has the same specimen thickness, taken from the literature to broaden the portfolio for calibration. The second part deals with conducting the finite element analysis, which provided a basis for the calibration of the phenomenological ductile fracture criterion applicable to crack-free bodies to indicate the crack initiation.</p><h3>Methods</h3><p>The steel frame to test thin specimens is designed with optical measurement of deformations. The finite element method is used, within Abaqus and user subroutines, to simulate the tests to obtain the variables needed for the calibration. In addition, the calibration of the criterion using machine learning is explored.</p><h3>Results</h3><p>The feasibility of the proposed experimental program is tested on the aluminium alloy 2024-T351. Moreover, the numerical simulations, which showed a good match with experiments in terms of force responses, adds to the knowledge of modelling in the scope of continuum damage mechanics.</p><h3>Conclusions</h3><p>The presented results provide a material basis for the aluminium alloy studied on a lower scale, while they broaden the testing possibilities and analyses the calibration strategies for the best failure predictability possible.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"64 9","pages":"1483 - 1495"},"PeriodicalIF":2.0,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01108-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142189299","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}