A mixed elastoplastic/rigid–plastic material model

Abstract

A new integration algorithm is described for large strain plastic deformations. The algorithm degenerates to the Euler forward elastoplastic-plastic model for small strain increments and to the rigid-plastic model for large strain increments. The model benefits from the advantages of both models: accuracy and fast convergence over a large range of strain increments.

Adaptive return mapping algorithms for J2 elasto‐viscoplastic flow

“…Taking = 1 2 coincides with the trapezoidal rule (mean normal), = 1 results in Euler backward integration (radial return). Huà etink et al [12] suggested to take as a function of the plastic multiplier in order to obtain an algorithm that is a mix between an elastoplastic and a rigid plastic method. This suggestion is elaborated in this paper to deÿne a class of adaptive integration algorithms for elasto-viscoplastic materials.…”

“…In other words, the integral is approximated by a weighted combination of the plastic-strain direction at the start and the end of the increment. Huà etink et al [12] proposed a model in which the constant weights of the generalized trapezoidal rule are replaced by weights dependent on the plastic multiplier. In this way an elastoplastic model was derived that degenerates to the rigid plastic model for large strain increments.…”