Stress overshooting solution for soil plasticity models

Abstract

This paper proposes a novel solution for mitigating the stress overshooting effect arising from advanced soil plasticity models. Stress overshooting is one of the main sources of numerical instability in finite element simulations of geomaterials with advanced plasticity models. Ensuring the robust performance of these models in numerical simulations is pivotal for modelling the behaviour of civil infrastructure under complex loading paths (e.g., dynamic and cyclic loads). Therefore, the paper first analyses and discusses the key limitations of some published models associated with stress overshooting effects. The remaining challenges are also highlighted. The results of the analyses show that definitions of plastic modulus and hardening laws have a significant impact on stress overshooting effects. Based on these analyses, we propose a robust overshooting solution and implement this solution using an explicit stress integration scheme with automatic sub-stepping to mitigate stress overshooting. By performing several numerical examples, we demonstrate the effectiveness and robustness of the proposed model in alleviating the stress overshooting effects.