Application of extended finite element method for fatigue life predictions of multiple site damage in aircraft structure

Abstract

This paper presents an application of the extended finite element method (XFEM) to the modelling of the propagation of four cracks in a typical aircraft structural configuration. It is a thin plate with three holes subjected to uniform uniaxial tensile stress. Material of the plate is aluminium alloy Al-2024 T3. Short theoretical background information is provided on the XFEM as well as the representation of cracks and the stress intensity factors computation. The accuracy of these computations is verified through super-position based approximate procedure and through finite element method (FEM) with singularity elements. The numerical results illustrate that XFEM is efficient for the simulation of crack propagation in MSD (Multiple Site Damage) without the need to re-mesh during the propagation if the finite element mesh is well defined.