Implicit stress-update algorithm for isotropic Cam-clay model based on the subloading surface concept at finite strains

摘要

A stress-update algorithm for the subloading surface Cam-clay model is developed. The model is re-formulated to be compatible with the multiplicative hyperelasto-plasticity for finite strains. The algorithm aims at synthesizing the phenomenological capability of the subloading surface model and the numerical advantage of the return mapping. A closed-form representation of the algorithmic tangent is also derived. The proposed algorithm is implemented into a finite-element code and is shown to be capable of producing accurate results even for large incremental steps. Numerical examples of boundary-value problems demonstrate the robustness of the algorithm.