Finite Element Implementation of the Exponential Drucker–Prager Plasticity Model for Adhesive Joints

Abstract

This paper deals with the numerical implementation of the exponential Drucker-Parger plasticity model in the commercial finite element software, ABAQUS, via user subroutine UMAT for adhesive joint simulations. The influence of hydrostatic pressure on adhesive strength was investigated by a modified Arcan fixture designed particularly to induce a different state of hydrostatic pressure within an adhesive layer. The developed user subroutine UMAT, which utilizes an associated plastic flow during a plastic deformation, can provide a good agreement between the simulations and the experimental data. Better numerical stability at highly positive hydrostatic pressure loads for a very high order of exponential function can also be achieved compared to when a non-associated flow is used.