Nonlocal strain regularisation for critical state models with volumetric hardening

The finite element (FE) method may suffer from numerical instability and mesh dependency when modelling the formation of shear bands using strain-softening constitutive models. Nonlocal methods have been shown to be capable avoiding these issues effectively. This paper proposes a novel generic algorithm for incorporating existing nonlocal into FE formulation elasto-plastic models with volumetric hardening laws. Using example modified Cam Clay (MCC) model this shows that instabilities are inevitable if plastic strains directly used update parameter. further robust regularisation overcome issue. has implemented bespoke code its capability in significantly reducing while maintaining stability is verified through series analyses biaxial compression tests highly overconsolidated clays. performance various also critically assessed.