Adaptive return mapping algorithms for J(2) elasto-viscoplastic flow

In this paper a new class of integration algorithms for elasto-viscoplastic constitutive equations is proposed. It is based on the generalized trapezo idal rule, which is a weighted combination of the start and end of the incr ement. But instead of taking constant weights, the weights are a function o f the plastic multiplier. In this way the magnitude of the plastic-strain i ncrement determines the way the integration is performed. The stress update and consistent tangent are derived for the case of J(2) flow. Several cand idates within the class of adaptive return mapping algorithms are investiga ted. It is shown numerically that some of the proposed algorithms are more accurate than commonly used algorithms such as mean normal and radial retur n. Copyright (C) 2001 John Wiley & Sons, Ltd.