Modeling of a crack propagating through a finite element mesh under mixed mode conditions is of prime importance in fracture mechanics. This paper presents an application of the finite element method to the analysis of crack growth problems in linear elastic fracture mechanics and the correlation of results with experimental data. In the present study, the crack growth simulation has been numerically simulated by using the finite element source code program using Visual FORTRAN language. This code includes the mesh generator based on the advancing front method as well as all the pre and post process for the crack growth simulation under linear elastic fracture mechanics theory. The maximum circumferential stress criterion has been used for prediction of the crack growth in isotropic materials under mixed-mode loading. Furthermore, the equivalent domain integral method has been used for calculating the stress intensity factors values during crack growth. The crack grows when the stress intensity factor exceeds the fracture toughness of the material in the case of static loading. Verification of the predicted crack path is validated with relevant experimental data and numerical results obtained by other researchers with a good agreement.

The aim of the present work was to develop a guideline for approving the railway axles made of C35 steel and containing surface and/or in-body defects after manufacturing. First, several through and part-through circular cracks were modeled on the surface and in the body of the axle at its critical cross-section. Then, the permissible size of such cracks was determined by using the fracture mechanics. To verify the validity of the guideline, the theoretical result for the semi-circular surface crack was compared with the allowable size prescribed by the international railway standard. A very good agreement was found to exist between the predicted and the standard values.