On the partitioning of the rate of deformation gradient in phenomenological plasticity

The rate of deformation gradient is partitioned additively into its elastic and plastic parts within the framework of phenomenological plasticity based on the multiplicative decomposition of deformation gradient. The corresponding partition of the nonsymmetric nominal stress is also given. The results are compared with the well-known results of partitioning the rates of Lagrangian strain and its conjugate symmetric Piola–Kirchhoff stress. Extension to the framework of monocrystalline plasticity is then discussed.