Implementation of material models for high strain rate applications as user-subroutines in abaqus/explicit

• Main Author: Bonorchis, Dean
• Other Authors: Cloete, T J
• Format: Dissertation
• Language: English
• Published: University of Cape Town 2016
• Subjects: Mechanical Engineering
• Online Access: http://hdl.handle.net/11427/17954

Includes bibliographical references. === The general purpose finite element program, Abaqus, has the facility to allow users to supplement its existing material model library with user-defined material models (VUMATs). This thesis involves the implementation and verification of the Johnson-Cook and Zerilli-Armstrong material models as VUMATs. The same version of the Johnson-Cook material model is contained in Abaqus and was therefore used as a benchmark. These material models are suitable for high strain, high strain rate and high temperature applications. The implementation of the material models was verified by comparing simulation results obtained using the Abaqus version of the Johnson-Cook material model with the simulation results obtained using the VUMATs of the Johnson-Cook and Zerilli-Armstrong material models. Firstly, this verification process was followed using single and multiple element tests with varying prescribed loading conditions. The verification process was then extended by performing a more "realistic" set of Taylor test simulations. The Taylor test simulation results were also compared with published experimental results for validation purposes.