An Implementation of Cyclic Cohesive Zone Models in ABAQUS and Its Applicability to Predict Fatigue Lives

Abstract

This paper deals with an implementation of cyclic cohesive zone models (CCZM) in ABAQUS and its application for predicting fatigue lives. Firstly, a brief introduction on cyclic cohesive zone models is given, followed by a detailed discussion of its use in ABAQUS. Two user subroutines (USDFLD and UDMGINI) are written in junction with a python script in order to predict the damage accumulation in a cyclic loading condition. This damage variable is later on used to update the parameters of a cohesive zone model, allowing the simulation of material degradation in a XFEM (with cohesive segments) element. This implementation allows the user to compute fatigue damage in a cycle-by-cycle approach, being possible to model both crack initiation and propagation phases. In this paper, we present results of low cycle fatigue using this approach. The results are then compared with literature data, providing a verification of the implementation and showing the efficiency of this methodology for dealing with fatigue problems.