Numerical simulation of interfacial crack growth under fatigue load

In the present paper, the interfacial crack growth of fibre reinforced composites under tension-tension cyclic load was simulated through the secondary development of the commercial finite element package ANSYS. For the importance of frictional degradation on the debonded interface during fatigue process, the modified power degradation model proposed in the authors' previous work is introduced into the present finite element analysis. Energy release rates rather than stress intensity factors are calculated in terms of difference approximation and utilized in Paris formula. Both looping cyclic load, calculating energy release rate, defining debond criterion and crack propagation law; updating parameters are programmed in ANSYS parametric design language, and the relationships between the parameters (such as the damage factor) and the number of cycles are obtained; the non-uniform stiffness degradation of matrix is taken into account. The numerical results are compared and discussed with the analytical solutions and good agreement is found. At the same time, a comparison between the present investigation and an experiment study is addressed.