Abstract:

Based on the work of Stumpf and Badur (1990) some problems related with the multiplicative decomposition F＝F^eF^p in finite elasto-plasticity have been investigated in detail. It is pointed out that there is no chance to supply an additional independent constitutive equation for plastic and/or elastoplastic spin since it can be represented, in general,by elastic and plastic stretches, as well as elastic and plastic deformation rates. It is especially for the case of rigid-finite plastic deformation suitable for metallic materials, the explicit representation of plastic spin, objective rate of back-stress and its relation with the Zaremba-Jaumann rate. Finally, a suitable way is pointed out that can supply an additional constitutive equation to plastic spin is the use of additive decomposition of elastoplastic deformation rates.

Key words: elasto-plasticity; finite deformation; deformation gradient decomposition; plastic spin