Analysis of advanced material models for complex industrial processes

Abstract

The work presented analyzes a number of associated and non-associated constitutive models and discusses their advantages and disadvantages. Additionally, new models are introduced to attempt to combine the advantages of both methods. To be able to evaluate a large number of models under similar conditions, all models tested have been implemented in a user defined subroutine written in Fortran90 for LS-Dyna. Based on previous work, an explicit integration algorithm was chosen for the material models, shortcomings of this algorithm have also been discovered and documented in this work. For general validation purposes,tests have been conducted to reproduce the strain distribution of Nakajima specimen. Additionally, a detailed analysis of 3D-strain distribution of industrial style deep drawing geometries has been the focus of this work to show the performance of material models for complex loading conditions. It is shown, that combined tension and compression is the most important load case for deep drawing applications and that material models optimized in this area show the greatest improvement. A number of additional influences have been investigated and discussed.