Effect of Compressive Residual Stress on the Corner Crack Growth

In the present study, plasticity induced crack closure (PICC) concept and three dimensional (۳D) finite element methods (FEM) are used to study the effect of compressive residual stress field on the fatigue crack growth from a hole. To investigate the effect of compressive residual stress on crack opening levels and crack shape evolution, Carlson’s experiments were simulated. Crack shape evolution is investigated by employing an automatic remeshing technique using MATLAB-ABAQUS code. The effect of mesh element size is considered by using element sizes of ۰.۰۲۵mm and ۰.۰۱۲۵mm. Crack opening level results indicate that the applied residual stress increases the opening levels with an average of ۴۵%. The higher opening levels results in higher number of fatigue cycles by a ratio of ۳.۰۷ for ۱.۹mm surface crack growth increment. Comparing the result obtained with Carlson’s experiments indicates that the crack closure method employed in the present analysis is in good agreement. Comparing the results with Jones’ supeposition method, moreover, illustrates that present paper method is more accurate.

کلیدواژه ها:

Residual stress ، Crack Closure ، FEM