Static shakedown theorem accounting for elastic stiffness degradation during plastic yielding

Abstract

The soil is modeled as coupled elastoplastic to account for the elastic stiffness degradation during plastic yielding. In such model the irreversible strain rate results from a combination of a plastic part and a coupled part of strain rates. The former arises from plastic yielding and the latter is generated by the variation in the elastic stiffness. This leads to non associated and coupled flow rules in which the outward direction of the irreversible strain rate do not coincides neither with the outward normal to the yield surface nor the outward normal to the plastic potential. In this paper an extension of the static shakedown theorem to soil is proposed in the framework of the coupled elastoplasticity