Analysis of two-dimensional fatigue crack propagation in thin aluminum plates using the Paris law modified by a closure concept

A general procedure is applied to analyze fatigue crack propagation in isotropic materials under mixed mode conditions, the Paris law modified by a closure concept. The dual boundary element method (DBEM) provides an stress and strain analysis on the solid, with reliable results for the mechanical fields in the region near to the crack tip. For validating purposes, thin plates made of 2024-T3 aluminum alloy are used with two horizontal notches. Throughout the J-Integral the stress intensity factors (SIFs) can be evaluated and with digital image processing, the displacement information from the experimental tests is obtained. Then, the effect of the crack closure during unloading is considered to attain remarkable numerical results compared to those experimentally collected, showing the feasibility of the proposed model.