Experimental Mechanics最新文献

{"title":"Shape Measurements of Lattice Materials from Few X-Ray Radiographs Using the 3D Virtual Image Correlation (3D-VIC) Method","authors":"L. Calmettes,&nbsp;M. L. M. François,&nbsp;J. Réthoré","doi":"10.1007/s11340-024-01116-3","DOIUrl":"10.1007/s11340-024-01116-3","url":null,"abstract":"<div><h3>Background</h3><p>the development of additive manufacturing technologies (3D printing) has made it possible to manufacture complex structures such as architected materials. However, traditional inspection methods are not suited to these materials, which require volume inspection to examine their internal structure.</p><h3>Objective</h3><p>the aim is to provide a 3D shape measurement method based on the initial computer-aided design (CAD) model used for 3D printing and X-ray radiographs.</p><h3>Method</h3><p>the CAD model is deformed until its virtual radiographs obtained by simulating the absorption of X-rays through the solid register with experimental radiographs. This registration is achieved by minimising a cost function with respect to the position of control points using radial basis function interpolation.</p><h3>Results</h3><p>the method’s performance is first evaluated using synthetic data. Its robustness is assessed with respect to image resolution, number of radiographs and noise level. Subsequently, the geometry of a solid with a tetrahedral architecture was quantified by means of a mere five radiographs. Global variation in shape and local defects in lattice structure can be detected.</p><h3>Conclusions</h3><p>the method enables the in-volume shape of architected materials to be checked without reconstructing the 3D computed tomography volume, but from just a few radiographs. It is robust and can detect local defects.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"55 - 68"},"PeriodicalIF":2.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995412","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":"MorphFlow: Estimating Motion in In-Situ Tests of Concrete","authors":"T. Nogatz,&nbsp;C. Redenbach,&nbsp;K. Schladitz","doi":"10.1007/s11340-024-01104-7","DOIUrl":"10.1007/s11340-024-01104-7","url":null,"abstract":"<div><h3>Background</h3><p><i>In situ</i> Computed Tomography is a valuable tool to investigate failure mechanics of materials in 3D. For brittle materials with sudden fracture like concrete however, state-of-the-art methods such as Digital Volume Correlation fail to produce displacement fields that display the discontinuous behavior of load induced cracking correctly.</p><h3>Objective</h3><p>The main objective is to develop an algorithm that calculates displacement fields for large-scale <i>in situ</i> experiments on concrete.</p><h3>Methods</h3><p>The algorithm presented is based on a 3D Optical Flow method solved by a primal-dual procedure and equipped with a coarse-to-fine scheme based on morphological wavelets. The algorithm is publicly available. Our evaluation focuses on the beneficial use of morphological wavelets over classical ones, and on the ability to produce reliable results with limited data. Applying the primal-dual scheme to <i>in situ</i> tests and using morphological wavelets are novel contributions.</p><h3>Results</h3><p>The results show that our algorithm cannot only cope with large volume images, but also produces discontinuous displacement fields that yield high strain in fractured regions. It does not only perform better than state-of-the-art methods, but also achieves sufficient results on reduced data. The morphological wavelets play a key role in this finding - they even allow to deduce cracks of widths less than a voxel.</p><h3>Conclusion</h3><p>Displacement calculation for <i>in situ</i> tests of brittle materials requires voxel-accurate displacement fields that allow for discontinuities. The presented algorithm fulfills these requirements and therefore is a powerful tool for future understanding of failure mechanics in concrete.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"35 - 53"},"PeriodicalIF":2.0,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01104-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994787","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":"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":"A Novel Method to In-Situ Characterize Fatigue Crack Growth Behavior of Nickel-Based Superalloys By Laser Thermography","authors":"C. Geng,&nbsp;Q. Zhong,&nbsp;H. Luo,&nbsp;W. Shi,&nbsp;H. Xie,&nbsp;W. He","doi":"10.1007/s11340-024-01113-6","DOIUrl":"10.1007/s11340-024-01113-6","url":null,"abstract":"<div><h3>Background</h3><p>Nickel-based superalloys are key materials for aero-engine hot-end components, and fatigue is one of their most typical failure forms. In the field of fatigue research, in-situ characterization of crack growth behavior is crucial, and more intuitive and accurate characterization methods need to be developed.</p><h3>Objective</h3><p>In this work, to better understand their fatigue crack growth behavior, we have developed new methods for in-situ characterization of crack growth behavior using laser thermography detection technique.</p><h3>Methods</h3><p>According to the thermal images of sample surfaces captured during the fatigue process, a method for positioning crack tip based on Prewitt edge detection is proposed, and a novel parameter, i.e., the crack opening temperature gradient (COTG), is defined to evaluate the crack closure effect.</p><h3>Results</h3><p>Based on the variation characteristics of COTG with load rate, the crack initial opening load rate (CIOLR) and crack opening load ratio (COLR) can be determined under different fatigue cycles. The results show that CIOTG and COTG tend to decrease with increasing fatigue cycles.</p><h3>Conclusion</h3><p>This work provides a visual and quantitative in-situ method for crack detection and characterization of the crack closure effect in fatigue testing.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"5 - 23"},"PeriodicalIF":2.0,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994563","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 INNOVative Approach for Mechanical Characterization of Coatings on Fibres","authors":"M. Benzarti,&nbsp;P. Henry","doi":"10.1007/s11340-024-01117-2","DOIUrl":"10.1007/s11340-024-01117-2","url":null,"abstract":"<div><h3>Background</h3><p>Varnish is used in many domains to enhance wear resistance, mechanical behaviour or chemical resistance. To characterize varnish cohesion or adhesion on plane surface, a scratch-test is predominantly used. In order to investigate coating properties on fibres, the common method uses tensile tests.</p><h3>Objective</h3><p>The aim of this paper was to investigate the adhesion of varnish on a monofibre of polyamide using an out of the box procedure based on scratch tests. To do so, a specific device was conceived to enable a scratch test on a single fibre.</p><h3>Methods</h3><p>Adhesion between varnish and a monofibre of nylon was investigated using several series of scratch tests on fibres coated by two types of varnish. Coating toughness and adhesion were investigated according to the coating composition and thermal treatment. A comparison between the different prints was discussed to characterize the effect of varnish type on the scratch resistance and to determine the parameters that influence this adhesion using scratch-test.</p><h3>Results</h3><p>The obtained results highlighted the influence of the thermal treatment imposed to the fibres on the mechanical behaviour. Tensile tests were conducted on the three types of samples in order to establish a link in terms of classification between a well-known characterization experiment and the presented scratch test.</p><h3>Conclusion</h3><p>Beyond the investigation of varnish/nylon fibre adhesion, this paper mostly aims at validating an innovative process for the characterization of coatings deposited on curved surfaces like fibres.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 1","pages":"25 - 34"},"PeriodicalIF":2.0,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994564","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":"Fatigue Damage Evolution in SS316L Produced by Powder Bed Fusion in Different Orientations with Reused Powder Feedstock","authors":"M. Kopec,&nbsp;U. Gunputh,&nbsp;G. Williams,&nbsp;W. Macek,&nbsp;Z.L. Kowalewski,&nbsp;P. Wood","doi":"10.1007/s11340-024-01118-1","DOIUrl":"10.1007/s11340-024-01118-1","url":null,"abstract":"<div><h3>Background</h3><p>Metal Laser Powder Bed Fusion Melting (LPBF-M) is considered economically viable and environmentally sustainable because of the possibility of reusing the residual powder feedstock leftover in the build chamber after a part build is completed. There is however limited information on the fatigue damage development of LPBF-M samples made from reused feedstock.</p><h3>Objective</h3><p>In this paper, the stainless steel 316 L (SS316L) powder feedstock was examined and characterised after 25 reuses, following which the fatigue damage development of material samples made from the reused powder was assessed.</p><h3>Methods</h3><p>The suitability of the powder to LPBF-M technology was evaluated by microstructural observations and measurements of Hall flow, apparent and tapped density as well as Carr’s Index and Hausner ratio. LPBF-M bar samples in three build orientations (Z – vertical, XY – horizontal, ZX – 45° from the build plate) were built for fatigue testing. They were then subjected to fatigue testing under load control using full tension and compression cyclic loading and stress asymmetry coefficient equal to -1 in the range of stress amplitude from ± 300 MPa to ± 500 MPa.</p><h3>Results</h3><p>Samples made from reused powder (25 times) in the LPBF-M process exhibited similar fatigue performance to fresh unused powder although a lower ductility for vertical samples was observed during tensile testing. Printing in horizontal (XY) and diagonal (ZX) directions, with reused powder, improved the service life of the SS316L alloy in comparison to the vertical (Z).</p><h3>Conclusions</h3><p>Over the 25 reuses of the powder feedstock there was no measurable difference in the flowability between the fresh (Hall Flow: 21.4 s/50 g) and reused powder (Hall Flow: 20.6 s/50 g). This confirms a uniform and stable powder feeding process during LPBF-M for both fresh and reused powder. The analysis of fatigue damage parameter, D, concluded cyclic plasticity and ratcheting to be the main mechanism of damage.</p></div>","PeriodicalId":552,"journal":{"name":"Experimental Mechanics","volume":"65 4","pages":"427 - 442"},"PeriodicalIF":2.0,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11340-024-01118-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143919306","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":"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}