FE model for linear-elastic mixed mode loading: estimation of SIFs and crack propagation

Finite element analysis combined with the concepts of linear elastic fracture mechanics provides a practical and convenient means to study the fracture and crack growth of materials. The onset criterion of crack propagation is based on the stress intensity factor, which is the most important parameter that must be accurately estimated and facilitated by the singular element. The displacement extrapolation technique is employed to obtain the SIFs at crack tip. In this paper; two different crack growth criteria and the respective crack paths prediction for several test cases are compared between the circumferential stress criterion and the strain energy density criterion. Several examples are presented to compare each criterion and to show the robustness of the numerical schemes.