A Theoretical and Numerical Research on Metal Criterion under Complex Stress States

Abstract

It is the fact that the complicity of structural details and loading conditions makes a great challenge of metal structure design.One of the most important aspects is to numerically predict the metal yield and failure behavior under complex stress state in a high accuracy.However,experimental results have revealed that the traditional von Mises criterion can not accurately predict yield behavior of metal under complex stress states.In order to improve the accuracy,a yield criterion modified by stress state parameters of triaxiality and Lode angle is proposed in this paper.Then modified yield criterion is implemented into ABAQUS/explicit with VUMAT user’s subroutine and applied to numerical analysis of 2024-T 4 coupons.Numerical and experimental results show that the proposed yield criterion can improve the prediction accuracy of metal yield under complex stress state than traditional von Mises criterion.

Keywords

• stress triaxiality
• lode angle
• complex stress state
• metal yield
• yield criterion