An analysis method for strain field of crack tip based on DIC technology and meshless method
Zhu Zhihui1,2 Feng Qianshuo1 Xiao Quanqing1 Luo Sihui1 Wang Fan1
1. School of Civil Engineering, Central South University, Changsha 410075, China；
2. National Engineering Laboratory for High Speed Railway Construction, Central South University, Changsha 410075, China
Abstract：Because it is difficult to obtain accurate crack tip strain fields by digital image correlation (DIC) technology, a hybrid method was proposed based on the DIC technology and element-free Galerkin (EFG) method. The meshless model was established by field nodes based on DIC technology. The diffraction method was used to consider the crack discontinuity and full-field stress and strain was calculated by the EFG method. The quasi-static cyclic tensile test was carried out on the compact tensile (CT) specimens made of Q235qE steel. The validity and stability of the method were verified by the analytical solution of crack tip strain and test results. Then, applications of DIC-EFG method in the plastic zone and stress intensity factor (SIF) calculation of crack tip were studied. Results show that, the DIC-EFG hybrid method is simple in modeling and can obtain the full-field strain including crack tip accurately without knowing loads and constraint conditions of the structure. Compared with the traditional DIC technology, the hybrid method may solve the problem of missing results near the crack, and it shall be more accurate in the calculation results of SIF when being in conjunction with J-integral method. The proposed method can be applied to the study of fracture properties such as the plastic zone and SIF calculation of fatigue crack.
朱志辉 冯乾朔 肖权清 罗思慧 王凡. 基于DIC技术和无网格法的裂尖应变场分析方法[J]. 土木工程学报, 2021, 54(6): 99-109.
Zhu Zhihui Feng Qianshuo Xiao Quanqing Luo Sihui Wang Fan. An analysis method for strain field of crack tip based on DIC technology and meshless method. 土木工程学报, 2021, 54(6): 99-109.
