应用数字图像相关方法测量含缺陷试样的全场变形

利用数字图像相关方法测量表面带孔洞、裂纹、缺口等缺陷试样的全场变形是许多实际测量任务中经常遇到的问题。就此问题，本文阐述了一种先对要避免计算的缺陷区域进行标记，在随后进行的相关计算中直接避免这些标记区域的方法。在已计算得到全场位移的情况下，文中提出了基于局部位移场最小二乘拟合的方法来计算区域边界、孔洞、裂纹或缺口附近等区域应变。最后对单侧边带半圆缺口试样的单向疲劳拉伸实验的计算结果充分显示本文方法的有效性和可靠性。

Full-field Deformation Measurement of Specimen with Discontinuity using Digital Image Correlation

Full-field deformation measurement of specimen with discontinuity using digital image correlation is a challenging task in many practical applications. In this paper, an improved digital image correlation method is proposed to overcome this problem. The discontinuity area is first artificially labeled and then directly overpassed in the subsequent calculation. Based on the calculated displacement field, local least-squares fitting technique of displacement field is proposed to calculate the strain field surrounding the discontinuity. The results from the tensile fatigue test of a low-carbon steel specimen with a one-side half-hole fully demonstrated the effectiveness and reliability of the proposed method.