“…The formulation uses Ogden's hyperelastic model (Ogden, 1972a,b) to predict the rubber-like nonlinear elastic response of the polymeric binder, and a hereditary (path-dependent) yield-surface-free endochronic plasticity theory (Valanis, 1970), based on the concept of internal state variables (Horstemeyer & Bammann, 2010), to account for irreversible deformations. A discontinuous isotropic damage model (Kachanov, 1986;Lemaitre et al, 1985) is utilized to model the stress-softening that occurs during unloading, and an endochronic material scale function (Valanis, 1970;Wu & Yip, 1981;Yeh, 1995;Lin et al, 2007) is utilized to model progressive cyclic stress softening and attainment of stable cyclic response. The number of model parameters is a function of the number of active Ogden terms and endochronic branches, and therefore a significant number of parameters may need to be identified.…”