基于数字图像相关方法的剪切带宽度的影响因素分析

Effects of Parameters on Shear Band Width Based on Digital Image Correlation Method

将粒子群优化算法引入到数字图像相关方法之中,利用两种相关系数公式,研究了样本子区的尺寸、相邻样本子区中心点在垂直于剪切带方向上的距离、最大迭代次数、剪切带宽度理论值和剪切带的剪切应变对剪切带宽度计算结果的影响。研究发现,随着样本子区尺寸的增加,剪切带宽度的测量结果越来越远离剪切带宽度的理论值;当剪切带的剪切应变较大时,随着样本子区尺寸的增加,剪切带宽度的计算结果变化较大;计算得到的剪切带的宽度通常都小于剪切带宽度的理论值,除非剪切带宽度的理论值或样本子区的尺寸取值较小时。

The particle swarm optimization algorithm is introduced into the digital image correlation method. And the influence of parameters on the shear band width is studied using two kinds of correlation coefficient formula, such as the subset size, the distance of two adjacent sub- sets in the normal direction of the shear band, iteration times, the theoretical value of the shear band width and the shear strain of the shear hand. It is found that the measured shear band width is more and more lower than the theoretical value of the shear band width as the subset size is increased. When the shear strain of the shear band is higher,the change of the measured shear band width is apparent as the subset size increases. The measured shear band width is usually lower than the theoretical value of the shear band width unless the shear band width or the subset size is lower.