On phase field modeling of ductile fracture

Abstract

AbstractRecently, different extensions of phase field fracture models to ductile fracture scenarios where the crack evolution is affected by plastic deformation have been proposed. In most of these phase field models for ductile fracture, the coupling of the elastic‐plastic material laws and the phase field variable is rather complicated and staggered finite element solution schemes are employed in order to avoid the computation of the complicated coupling terms in the tangent matrix. In this work, we propose an elastic‐plastic phase field fracture model, where the coupling is such that a monolithic solution is possible. Through the proposed coupling of the elastic‐plastic material law and the phase field order parameter, a reinterpretation of the meaning of the plastic material parameters is necessary in order to obtain reasonable effective material properties for the ductile phase field fracture model that can be related to measured data. The respective relations are derived from an analysis of the model in one dimension. Finite element simulations of plane strain fracture problems demonstrate the appropriateness of the derived effective material parameters and the applicability of the monolithic solution scheme. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)