ALGORITHMIC TANGENT MATRIX APPROACH FOR MIXED HARDENING MODEL OF ENDOCHRONIC PLASTICITY

A three-dimensional (3-D) algorithmic tangent matrix approach is devel oped for elastoplastic finite element (FE) analysis using the mixed ha rdening model of the endochronic plasticity. The simple radial return algorithm is implemented in the development of the underlying strain-c ontrolled integration algorithm, which is unconditionally stable. Prec ise implementation of the radial return is due to the use of the expon ential algorithm. The 3-D formulation is applied to FE micromechanics modeling of a undirectional metal matrix composite subjected to non-pr oportional transverse-normal longitudinal-shear cyclic loading. The pr edicted macroscopic and microscopic responses consistently demonstrate the computational advantages of the present approach.