An algorithm for large-scale computational finite-deformation plasticity

Abstract

This paper describes the results of an extended version of a new explicit algorithm recently developed by Nemat-Nasser and co-workers for stiff phenomenological finite-deformation rate-independent elastoplasticity and rate-dependent elastoviscoplasticity. The extended algorithm incorporates effects of large strains and rotations, while continuing to include possible combined isotropic and kinematic workhardening, as well as thermal softening and noncoaxiality of the plastic strain rate and the deviatoric stress. It is based on a plastic-predictor-followed-by-elastic-corrector methodology and produces accurate and stable results, which are practically (i.e., in a finite-element application) independent of the magnitude of the time or strain increment. It is shown that the algorithm provides accurate results for relatively large strain and rotation increments. The result is exact for rigid-body rotation. It also works well for problems with nonproportional loading.