Application of the Boundary Element Method to Inelastic Fracture Mechanics

Abstract

The numerical results presented here cover fatigue crack growth modeling of a two-dimensional problem. The study mainly focuses on the comparison of elastoplastic crack opening for long and short cracks under plane stress and plane strain conditions. The numerical results are obtained by using the elastoplastic boundary element method (BEM).

Previously published results by many authors have shown the correlating role of stress intensity factor in linear elastic fracture mechanics (LEFM). However, others [1–4] have shown that the elastic stress intensity factor from LEFM does not correlate all crack data for problems with high applied stress, relative to the material yield stress. The crack sizes corresponding to these data are quite small compared to the crack sizes used for laboratory characterization of crack growth. In a recent review by Leis, et al. [1] the so-called small flaw modeling problem is attributed to a lack of similitude, i.e., the damage process in the material ahead of the crack does not scale below a certain crack size. Those who argue this situation must seek a new measure that reduces to LEFM for the appropriate cases.