On exploiting the weak invariance of multiplicative elasto-plasticity for efficient numerical integration

ABSTRACT The talk is devoted to the efficient and robust numerical integration of constitutive equations governing finite strain elasto-plasticity. We utilize in a consistent manner the approach based on numerous multiplicative decompositions of the deformation gradient. The nonlinear kinematic hardening is incorporated basing on the approach of Lion [1], the nonlinear distortional hardening is introduced through its generalization presented in The key notion of the talk is the property of so-called weak invariance of constitutive relations under isochoric change of the reference configuration The resulting algorithms are first order accurate and unconditionally stable. Moreover, they exactly preserve the restriction of inelastic incompressibility which supresses the error accumulation. Numerical tests are used to compare the new algorithms with some known modifications of the classical Euler backward method