摘要：In this paper an extension of a large strain elastoplastic constitutive model
based on hyperelasticity and multiplicative decomposition of deformation
gradient tensor due to García Garino is extended to viscous case following a
previous work of Ponthot based on Perzyna type model. The integration of
constitutive model is based on numerical scheme originally designed for the
elastoplastic problem that naturally includes the rate dependent case.
Consequently the algorithm proposed by Ponthot for viscoplasticity is easily
taken into account in the framework of hyperelasticity and irreversible
thermodynamics of solids. For the case of metals, a unified stress update
algorithms for elastoplastic and elasto-viscoplastic constitutive equations
submitted to large deformations is obtained. The plastic corrector step is, in
case of J2 flow theory material behavior, an extension to the viscoplastic range
of the classical radial return algorithm for plasticity. The resulting unified
implicit algorithm is both efficient and very inexpensive. Moreover, if there is
no viscosity effect (rate-independent material) the presented algorithm
degenerates exactly into the classical radial return algorithm for plasticity.
