EXPERIMENTAL AND THEORETICAL ANALYSES OF THREE- DIMENSIONAL SURFACE CRACK PROPAGATION
LI Liyun1，WONG R H C2，HAN Zhichao1，LI Haiyun1，LIU Yi1
(1. School of Mechanics and Civil Engineering，China University of Mining and Technology，Beijing 100083，China；
2. School of Civil and Environmental Engineering，The Hong Kong Polytechnic University，Hong Kong，China)
Abstract：An experimental investigation on three-dimensional(3D) surface crack under biaxial compression is conducted to investigate the growth of wing crack and anti-wing crack. A digital speckle camera is used to record the growth process of cracks during loading process. The images captured from the digital speckle camera are used for digital speckle correlation analysis to study the strain field of 3D surface crack. From the experiments，it is observed that the anti-wing crack initiates away from the crack tip region and then propagates towards the crack tip. The stress and the stress intensity factors along crack front are analyzed by using the finite element method. 3D wing crack growth pattern is revealed by the mixed-model fracture criteria. The theoretical analyses indicate that the wing crack propagation can be predicted by the maximal circumferential stress criterion and maximal circumferential strain criterion . The strength failure analysis is also conducted in the anti-wing crack area. The anti-wing initiation and propagation can be predicted by the Mohr-Coulomb strength theory. The whole fracture and failure process of the 3D surface crack is analyzed by both experiments and theories.
2012, Vol. 31 
