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Conference Paper/Proceeding/Abstract 1243 views

A new method for predicting fatigue crack growth rates using Abaqus

Will Harrison Orcid Logo, W.J. Evans

Abaqus UK Regional Users Meeting

Swansea University Author: Will Harrison Orcid Logo

Abstract

The aim of this project was to accurately predict fatigue crack growth rates using only data obtained from strain controlled tests. Mode 1 crack growth was simulated by a series of static Abaqus analyses with the crack growth rate calculated by dividing the increment of crack movement by the life be...

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Published in: Abaqus UK Regional Users Meeting
Published: 2008
URI: https://cronfa.swan.ac.uk/Record/cronfa29847
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Abstract: The aim of this project was to accurately predict fatigue crack growth rates using only data obtained from strain controlled tests. Mode 1 crack growth was simulated by a series of static Abaqus analyses with the crack growth rate calculated by dividing the increment of crack movement by the life between each analysis. The Abaqus Scripting Interface was used to draw the crack dimensions for each analysis and also to extract the relevant stress and strain data from output database file (.odb). The stress and strain values were then used to calculate the fatigue damage at each integration point, and hence the life between increments, based on the Walker life relationship.This paper outlines the methods used in developing the model. A description of Chaboche’s non-linear isotropic/kinematic hardening model is given along with a description of the Walker strain and how it is used to predict plane specimen fatigue lives. The Walker method is then used to predict the initiation lives of double-edge notched (DEN) specimens with results consistent with experimental data. The paper then shows how this method is extended to predicting the lives of nodes ahead of an advancing fatigue crack with the model showing a good correlation between predicted crack growth rates and those obtained experimentally. A close examination of the stress field around the crack tip was made and the importance of the monotonic and cyclic plastic zone sizes was investigated.
College: Faculty of Science and Engineering