Customized user implementation of material models in PAK- S software

Abstract

Relationships between stresses and strains are constitutive relations. The behavior of the materials depends on the material characteristics, which are contained in the constitutive relations. By defining the constitutive relations and by knowing the material characteristics, it is possible to simulate the response of the material for small and large strains by implementation into the FEM software. The aim of this work is to develop a subprogram that will represent an interface for the easy implementation of a user material models into the FEM software PAK- S for the structural analysis. Researchers and engineers often struggle to develop and implement constitutive models for the simulation of various materials in FEM- based software. The reasons are complicated procedures and difficulties related to the features of the FEM software. The implemented interface was tested and verified for the linear elasticity, Von Mises plasticity, and shape memory alloys constitutive model. The importance of this interface is reflected in the fact that it enables easier use of already existing, but also easier implementation of new constitutive user models.