Strain最新文献 - Book学术

Quantification of localised strains induced within a granular medium by a biphasic flow via digital image correlation 通过数字图像相关性量化双相流在颗粒介质中引起的局部应变

IF 2.1 3区材料科学

Strain Pub Date : 2024-06-13 DOI: 10.1111/str.12480

Rana Al Nemer, Julien Réthoré, Giulio Sciarra

引用次数: 0

Multiscale 3D displacement field measurement using stereo digital image correlation on a fractal speckle pattern 利用分形斑点模式上的立体数字图像相关性进行多尺度三维位移场测量

IF 2.1 3区材料科学

Strain Pub Date : 2024-05-15 DOI: 10.1111/str.12479

J. Serra, R. Lalanne, J.‐E. Dufour, J. Perie, J.‐C. Passieux

{"title":"Multiscale 3D displacement field measurement using stereo digital image correlation on a fractal speckle pattern","authors":"J. Serra, R. Lalanne, J.‐E. Dufour, J. Perie, J.‐C. Passieux","doi":"10.1111/str.12479","DOIUrl":"https://doi.org/10.1111/str.12479","url":null,"abstract":"Even though the simulations used to predict failure are becoming increasingly predictive, complex multiaxial loading tests are still required to validate the design of structural components in a wide range of industries. Large specimen testing often requires two different scales. A global Far Field to obtain boundary conditions and a local Near Field to evaluate strain gradients around discontinuities such as bolts, notches… The main goal of this study is to provide a continuous displacement over the whole specimen surface integrating data from multiple cameras. In this paper, we propose a new methodology that generates 3D displacements determined by finite‐element stereo digital image correlation in the Near Field and in the Far Field using a unique fractal speckle pattern and an off‐line determined texture. The displacements are obtained in the same coordinate system and on the same mesh. Satisfactory data fusion from both Near Field and Far Field images of a biaxial test on a notched laminate composite was obtained with a refined mesh at the notch tip. This methodology can be applied to any tests requiring multiple camera systems and will support the use of the finite‐element digital image correlation framework as an experimental‐numerical efficient technique.","PeriodicalId":51176,"journal":{"name":"Strain","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140975139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Image‐based inertial impact test for viscoelastic constitutive identification: A digital replica for error quantification 基于图像的惯性冲击试验，用于粘弹性结构识别：误差量化的数字复制品

IF 2.1 3区材料科学

Strain Pub Date : 2024-05-10 DOI: 10.1111/str.12476

A. Matejunas, L. Fletcher, L. Lamberson

{"title":"Image‐based inertial impact test for viscoelastic constitutive identification: A digital replica for error quantification","authors":"A. Matejunas, L. Fletcher, L. Lamberson","doi":"10.1111/str.12476","DOIUrl":"https://doi.org/10.1111/str.12476","url":null,"abstract":"Polymers find widespread use in applications where they are subjected to impact loading. Therefore, understanding the time dependence of their mechanical response is critical to the design of structures subjected to these high strain rate environments. However, characterising these materials on microsecond time scales has proven challenging. Traditional experimental techniques rely on satisfying a number of limiting assumptions and typically do not provide direct measurements of the material parameters. Here, we propose a novel implementation of the image‐based inertial impact (IBII) test to extract viscoelastic constitutive parameters on these microsecond time scales using the stress gauge implementation of the virtual fields method. We validate the experiment using a digital replica approach in which the constitutive parameters are first extracted on a finite element model of an IBII test on a viscoelastic material. The finite element data are then used to synthetically deform computer‐generated grid images, which are then polluted with grey‐level noise to simulate the images that would be captured in a real‐life experiment. These images are processed identically to a physical experiment, and the identification is repeated using the full‐field displacements extracted from the computer‐generated images to determine the ideal processing parameters. Parameter identification was found to strongly depend on the processing parameters used to extract the kinematic fields from full‐field images, emphasising the need for computational validation before attempting a physical experiment to extract constitutive parameters. The IBII experimental method was found to be capable of simultaneously identifying the bulk modulus and the shear modulus along with their associated time constant.","PeriodicalId":51176,"journal":{"name":"Strain","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140991516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental approach for characterizing the nonlinear, time and temperature‐dependent constitutive response of open‐cell polyurethane foams 表征开孔聚氨酯泡沫非线性、随时间和温度变化的构成响应的实验方法

IF 2.1 3区材料科学

Strain Pub Date : 2024-05-09 DOI: 10.1111/str.12478

J. Tao, Xiangyu Sun, Christian Franck

{"title":"Experimental approach for characterizing the nonlinear, time and temperature‐dependent constitutive response of open‐cell polyurethane foams","authors":"J. Tao, Xiangyu Sun, Christian Franck","doi":"10.1111/str.12478","DOIUrl":"https://doi.org/10.1111/str.12478","url":null,"abstract":"Elastomeric foams are composite materials comprising of a polymeric elastomer and interconnected gas‐filled pores, endowing them with exceptional compliance and the ability to undergo large, reversible deformations along with substantial volume change. These foams find extensive utility in contexts demanding compliance and compressibility, such as impact protection and cushioning, spanning a diverse range of applications. Changing temperature can dramatically alter foam stiffness, strength and deformation characteristics specifically around the material's glassy‐rubbery transition temperature (). With the aim of informing new constitutive model developments for elastomeric foams, we conducted a comprehensive series of large deformation, homogeneous compression and tension tests across strain rates from 10−2 s−1 to 100 s−1 and ambient temperatures ranging from −10°C to 50°C covering an even range around the material's of 20°C. To achieve precise control of ambient temperatures during mechanical testing, we constructed a custom‐designed environmental chamber for controlling the ambient temperature from −10°C to 50°C with a variation of less than 1°C. The obtained digital image correlation based stress‐strain data shows significant tension‐compression asymmetry as well as significant dependence on strain rate and ambient temperature, especially above and below the glass transition temperature. We provide full access to these data sets for the future development of rate‐ and temperature‐dependent constitutive models.","PeriodicalId":51176,"journal":{"name":"Strain","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140997735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An artificial neural network for digital image correlation dynamic subset selection based on speckle pattern quality metrics 基于斑点模式质量指标的数字图像相关动态子集选择人工神经网络

IF 2.1 3区材料科学

Strain Pub Date : 2023-12-21 DOI: 10.1111/str.12471

D. Atkinson, M. van Rooyen, T. H. Becker

{"title":"An artificial neural network for digital image correlation dynamic subset selection based on speckle pattern quality metrics","authors":"D. Atkinson, M. van Rooyen, T. H. Becker","doi":"10.1111/str.12471","DOIUrl":"https://doi.org/10.1111/str.12471","url":null,"abstract":"Precise and accurate digital image correlation computed displacement data requires sufficient noise suppression and spatial resolution, which improve and diminish, respectively, with increased subset size. Furthermore, spatially varying speckle pattern quality and displacement field complexity ideally necessitate a location‐specific optimal subset size to obtain a favourable compromise between noise suppression and spatial resolution. Although dynamic subset selection (DSS) methods have been proposed based on speckle pattern quality metrics (SPQMs), they do not ensure such a favourable compromise.This work investigates using an artificial neural network (ANN) for DSS. An ANN is trained to predict the displacement error standard deviation of a subset from multiple SPQMs and the standard deviation of image noise, such that the smallest subset offering sufficient noise suppression, dictated by a displacement error standard deviation threshold, is appointed.Validation, both within and outside the domain of the training images, shows that the smallest subset providing sufficient noise suppression offers a favourable compromise for up to moderate displacement gradients. Additionally, the proposed method is shown to perform with greater consistency and reliability relative to existing SPQM‐based DSS methods.The novel proposition lies in utilising an ANN as an error prediction tool, based on multiple SPQMs, and hence, is an attractive alternative for DSS.","PeriodicalId":51176,"journal":{"name":"Strain","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138953113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A comparative study of Glinka and Neuber approaches for fatigue strength assessment on 42CrMoS4‐QT specimens 对 42CrMoS4-QT 试样进行疲劳强度评估的格林卡和纽伯方法比较研究

IF 2.1 3区材料科学

Strain Pub Date : 2023-12-20 DOI: 10.1111/str.12470

Philipp Thumann, Stefan Buchner, Steffen Marburg, Marcus Wagner

{"title":"A comparative study of Glinka and Neuber approaches for fatigue strength assessment on 42CrMoS4‐QT specimens","authors":"Philipp Thumann, Stefan Buchner, Steffen Marburg, Marcus Wagner","doi":"10.1111/str.12470","DOIUrl":"https://doi.org/10.1111/str.12470","url":null,"abstract":"In fatigue strength assessment, the methods based on ideal elastic stresses according to Basquin and the less established method based on elastic‐plastic stress quantities according to Manson, Coffin and Morrow are applied. The former calculates loads using linear‐elastic stresses, the latter requires elastic‐plastic evaluation parameters, such as stresses and strains. These can be determined by finite element analysis (FEA) with a linear‐elastic constitutive law, and subsequent conversion to elastic‐plastic loads, using the macro support formula by Neuber. In this contribution, an alternative approach to approximate elastic‐plastic parameters proposed by Glinka is compared to the the strain‐life method using Neuber's formula, as well as the stress‐life method of Basquin. Several component tests on 42CrMoS4‐QT specimens are investigated. To determine the input data for the fatigue strength evaluations, the entire test setup is computed by FEA. The nodal displacements from these validated full‐model simulations are used as boundary conditions for a submodel simulation of a notch, whose results serve as input for the fatigue strength assessments. It is shown that all approaches provide a reliable assessment of components. Our key result is that the strain‐life method using the concept by Glinka for notch stress computation, yields improved results in fatigue strength assessments.","PeriodicalId":51176,"journal":{"name":"Strain","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138954147","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biaxial expansion due to compression experiments for measuring the failure strain of tubular samples 测量管状样品破坏应变的压缩双轴膨胀实验

IF 2.1 3区材料科学

Strain Pub Date : 2023-08-31 DOI: 10.1111/str.12462

M. Bono, A. Zouari, T. Le Jolu, D. Le Boulch, H. Tabouret, J. Crépin, J. Besson

{"title":"Biaxial expansion due to compression experiments for measuring the failure strain of tubular samples","authors":"M. Bono, A. Zouari, T. Le Jolu, D. Le Boulch, H. Tabouret, J. Crépin, J. Besson","doi":"10.1111/str.12462","DOIUrl":"https://doi.org/10.1111/str.12462","url":null,"abstract":"The failure strain of a tube is a function of the biaxial strain ratio (axial strain/hoop strain) to which it is subjected. The relationship between failure strain and the strain ratio can be determined experimentally using expansion due to compression tests with a tensile load (EDCT), in which a ductile pellet placed inside the tube is compressed axially so it expands in diameter and imposes a hoop strain on the tube. At the same time, a tensile load on the ends of the tube creates an axial strain. This study investigates the capabilities and limitations of EDCT tests using two devices that allow experiments to be performed on a standard tensile testing machine. The first device applies an axial force on the ends of the sample, and the second device applies an axial displacement. Tests on zirconium alloy tubes confirmed that the failure strain is dependent on the strain ratio and the metallurgical state of the material. EDCT tests can produce a range of strain ratios, but there is an upper limit on the strain ratio that can be obtained, and it is dependent on the plastic behaviour of the sample and the friction conditions between the components.","PeriodicalId":51176,"journal":{"name":"Strain","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48775850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the use of an induced temperature gradient and full‐field measurements to investigate and model the thermomechanical behaviour of an austenitic stainless steel 316 关于使用感应温度梯度和全场测量来研究和模拟奥氏体不锈钢316的热机械行为

IF 2.1 3区材料科学

Strain Pub Date : 2023-07-30 DOI: 10.1111/str.12460

G. C. Soares, Arturo Rubio Ruiz, M. Hokka

引用次数: 0

Numerical and experimental investigation of the residual stress distribution of internal thread cold extrusion and tap wear 内螺纹冷挤压及丝锥磨损残余应力分布的数值与实验研究

IF 2.1 3区材料科学

Strain Pub Date : 2023-07-27 DOI: 10.1111/str.12459

Nianqing Wan, Qiang He, X. Jing, Yonggang Jiang, Honggen Zhou

引用次数: 0

Unified digital image correlation under meshfree framework 无网格框架下的统一数字图像相关

IF 2.1 3区材料科学

Strain Pub Date : 2023-07-27 DOI: 10.1111/str.12461

Bin Chen, S. Coppieters

引用次数: 0