Numerical and Experimental Investigations of Curved Fatigue Crack Growth under Biaxial Proportional Cyclic Loading

The paper presents numerical and experimental results of continued studies of curved fatigue crack growth in arbitrarily pre-cracked isotropic sheets under biaxial proportional plane loading. The predictor-corrector method (PCM) was extended in order to analyse the growth of multiple crack systems. As a result, the program PCCS-2D was written to run within ANSYS without any user interaction. In order to check the accuracy and efficiency of the method biaxial crack growth simulations were carried out for a fracture mechanics cruciform specimen. The results are compared with experimental findings obtained by specimens made of 6061 aluminium alloy in T651 condition using a 250kN biaxial servohydraulic testing machine. From the numerical and experimental results, we conclude, that the proposed predictor-corrector method can be used in curved crack growth simulation also under biaxial proportional loading conditions.