Implementation of hill orthotropic criterion in finite strain elastoplasticity for sheet metal forming

Abstract

In order to develop a three dimensional finite element computer program related to the sheet metal forming process modeling for car industry, we are currently implementing an adapted finite elastoplastic strain module. Our aim is then to progress in representing the deep drawing steel behaviour, especially to describe a wide range of complex strain paths. This module is based on a large strain membrane formulation using a set of curvilinear coordinates and the classical Hill orthotropic criterion with non-associated (or associated) plastic flow rule and mixed (isotropic and/or kinematics) hardening. Experimental/numerical comparisons on testing cups have been carried out and discussed to select the suitable hypotheses. © 1990.