A SEMIIMPLICIT INTEGRATION SCHEME FOR RATE-DEPENDENT AND RATE-INDEPENDENT PLASTICITY

A semi-implicit constitutive integration procedure for rate-independen t and rate-dependent inelastic flow of metals is presented. This integ ration scheme, originally proposed by Moran et al. [Formulation of imp licit finite element methods for multiplicative finite deformation pla sticity. Int. J. Numer. Meth. Engng 29, 483-514 (1990)], has the featu re of being explicit in the plastic flow direction and hardening modul i but implicit in the incremental plastic strain. Two approaches to th is scheme are devised for rate-dependent constitutive relations, denot ed herein as the kinetic equation and the dynamic yield condition appr oaches. Details of the integration scheme are developed and applied to both incompressible and compressible inelasticity, including pure iso tropic and combined kinematic-isotropic hardening theories. Both rate- and temperature-dependent and rate- and temperature-independent const itutive laws are considered. In addition, the explicit version of this scheme is obtained, resulting in the rate tangent modulus method. (C) 1997 Elsevier Science Ltd. All rights reserved.