TY  - EJOU
AU  - Karšaj, Igor 
AU  - Sansour, Carlo 
AU  - Sorić, Jurica 

TI  - A new free energy-based model of the kinematic hardening in large strain elastoplasticity
T2  - Computer Modeling in Engineering \& Sciences

PY  - 2005
VL  - 8
IS  - 1
SN  - 1526-1506

AB  - In this paper, a free energy-based formulation incorporating the effect of kinematic hardening is proposed. The formulation is able to reproduce symmetric expressions for the back stress while incorporating the multiplicative decomposition of the deformation gradient. Kinematic hardening is combined with isotropic hardening where an associative flow rule and von Mises yield criterion are applied. An accurate and trivial wise objective integration algorithm employing the exponential map is developed. In order to ensure a high convergence rate in the global iteration approach, an algorithmic tangent operator is derived. The computational algorithm is implemented and applied to a shell finite element which allows the use of complete three-dimensional constitutive laws. Robustness and efficiency of the proposed algorithm are demonstrated by numerical examples.
KW  - large strains
KW  -  elastoplasticity
KW  -  free energy
KW  -  kinematic hardening
KW  -  isotropic hardening

DO  - 10.3970/cmes.2005.008.045