An extension of the radial return algorithm to account for rate-dependent effects in frictional contact and visco-plasticity

This paper deals with unified elasto-plastic and elastic-visco-plastic constitutive equations for metals submitted to large deformations. We present here a newly developed time integration algorithm which is an extension to the visco-plastic range of the classical radial return algorithm for plasticity. The resulting implicit algorithm is both efficient and very inexpensive. This algorithm is also subsequently extended to frictional problems where it allows a generalisation of the classical Coulomb dry friction criterion to a criterion depending on the relative slip velocity such as those encountered in the hydrodynamic regime. (C) 1998 Elsevier Science S.A. All rights reserved.