基于局部位移场最小二乘拟合数字图像相关方法的剪切带应变测量  

Strain Measurements of Shear Bands Based on Least-square Fitting of Local Displacements Based on the Digital Image Correlation Method

作　　者：王学滨 侯文腾[2] 董伟 杨梅 曹思雯[2] WANG Xue-bin;HOU Wen-teng;DONG Wei;YANG Mei;CAO Si-wen(Institute of Computational Mechanics,Liaoning Technical University,Fuxin,Liaoning 123000,China;College of Mechanics and Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,China;School of Mechanical Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,China)

机构地区：[1]辽宁工程技术大学计算力学研究所,辽宁阜新123000 [2]辽宁工程技术大学力学与工程学院,辽宁阜新123000 [3]辽宁工程技术大学机械工程学院,辽宁阜新123000

出　　处：《计量学报》2019年第4期655-661,共7页Acta Metrologica Sinica

基　　金：国家自然科学基金(51574144);辽宁省百千万人才工程资助项目(2017)

摘　　要：采用局部位移场最小二乘拟合数字图像相关方法测量了虚拟剪切带的应变,并将测量结果与中心差分方法的结果和理论解进行了对比,主要研究了计算窗口尺寸和子区尺寸的影响。研究发现:当子区尺寸较小且应变计算窗口尺寸较大时,局部位移场最小二乘拟合数字图像相关方法的测量结果接近于理论解;对于测量单轴压缩条件下低液限黏土试样破坏过程中的应变场,局部位移场最小二乘拟合方法的测量结果比中心差分方法测量结果更准确,有助于对剪切带应变的准确测量。Strains in the fictitious shear band are measured by use of least-square fitting of local displacements of the digital image correlation method,and strains are compared with those obtained by use of the central difference method and the analytical solution.Effects of the size of the calculating window and the size of the subset are mainly demonstrated.It is found that when the calculating window is larger and the size of the subset is lower,strains are closer to the analytical solution.Strains during the failure process of the low liquid-limit clay specimen under uniaxial compression are measured by use of least-square fitting of local displacements method and the central difference method,and strains are measured by least-square fitting of local displacements method are more accurate,which is helpful for the accurate measurement of strains of shear bands.

关 键 词：计量学 剪切带 应变 最小二乘拟合 数字图像相关方法 黏土 梯度塑性理论 

分 类 号：TB931[一般工业技术—计量学]