Abstract:The SIFs solutions of CTS specimen are used to investigate the I/II mixed-mode fracture behavior, but they are not applicable for the deflected crack. In this study, three dimensional fracture analyses of CTS specimen for mixed-mode I/II loading are performed using finite element method (FEM). To simulate the real conditions, the contacts between the contact surfaces of the loading device, specimen and the pins. Comparison between the FEM results and the solutions for SIFs of CTS specimen were done for verification of the proposed simulation method. The crack growth paths of the CTS specimen for all loading angles are simulated by following the MTS principle. The SIFs of the crack front with the crack growth length were given, and the reason of the crack growth paths not perpendicular with the direction of the traction force was found. The mixed-mode crack growth rate can be obtained by combining the proposed SIFs results with thea-N test results.