Description of non-linear unloading curve and closure of cyclic stress-strain loop based on Y-U model

Abstract

This paper proposes a cyclic elasto-plasticity model to describe non-linear unloading-reloading curves and closure of a cyclic stress-strain hysteresis loop based on the Yoshida-Uemori (Y-U) model. The nonlinear unloading stress-strain response is expressed by an equation for the stress-dependent Young’s modulus in the yield surface. The closure of a cyclic stress-strain curve is described by automatically changing Y-U material parameters. The great advantage of the above approaches is that no additional parameters are needed.