Mixed-mode fatigue crack growth analysis using peridynamic approach

A new method is developed in this study to extend the peridynamic fatigue model for mode-I crack case proposed by Silling (2014) to a mixed-mode (mode-I and mode-II) crack case. To determine the model parameters, application of the modified Paris law incorporating the effective stress intensity factor model of Tanaka (Tanaka, 1974), is also proposed. Furthermore, a method is developed to decompose the peridynamic J-integral separately into mode-I and mode-II. The decomposed J-integral values are then used to compute and analyze the change in the stress intensity factor of each mode during crack propagation. The proposed model is validated by comparison with existing experimental results and shows that a mixed-mode fatigue crack growth rate can accurately be predicted under various load conditions. Additionally, the associated computation time is significantly reduced by formulating a matrix-based peridynamic code that uses a graphics processing unit.