A comparative study of linear elastic and elasto plastic fracture modeling by XFEM

Abstract

In the present work, a comparative analysis has been presented between linear elastic and elasto-plastic fracture modelling of ductile structures using extended finite element method (XFEM). Three different fracture models namely “linear elastic fracture model (LEFM)”, “elasto-plastic fracture model (EPFM) with LEFM branch functions” and “elasto-plastic fracture model with EPFM branch functions” are implemented to check effectiveness of individual modelling approach for ductile structures. The non-linear consecutive relation of the elasto-plastic material is modelled by Ramberg-Osgood equation. The plasticity condition has been checked by isotropic hardening and von-Mises failure criterion. Further, Newton-Raphson iterative scheme has been used to solve nonlinear discrete equations. Few numerical cases are solved by all three presented approaches and comparative results are presented in the form of J-integral.