A hypoelasto-viscoplastic endochronic model for numerical simulation of shear band localization

In this paper, a hypoelasto-viscoplastic endochronic model is developed to capture the strain localization phenomena. The elastic response is stated in terms of hypoelastic model and endochronic constitutive equations are stated in unrotated frame of reference. The infinitesimal theory of endochronic plasticity is extended to large strain range on the basis of the additive decomposition of the strain rate tensor and hypoelasticity. Constitutive equations are stated in unrotated frame of reference that greatly simplifies endochronic constitutive relations in finite plasticity and yields the efficiency of the presented algorithm by total uncoupling material and geometrical nonlinearities. An implicit scheme is employed, which is the efficient method for the type of nonlinear problems considered here. Finally, the efficiency of the proposed constitutive model and computational algorithms is demonstrated by evolution of the shear band in a plane strain strip and vertical slope with strain softening endochronic plasticity.