A Masing-Type Modelling Concept for Cyclic Plasticity at Elevated Temperature

Abstract

Classical plasticity models commonly apply a yield surface concept for the formulation of elastic-plastic constitutive behaviour. This inherently implies a discontinuous transition between the elastic and plastic deformation regime. In the absence of a direct physical interpretation, the identification of the model parameters is further strongly affected by the adopted elastic modulus and yield stress. A continuous Masing-type model formulation is suggested that effectively represents the continuous elastic-plastic behaviour of a low-alloy steel (2CrMoNiWV). The small number of four model parameters allows for a straight-forward parameter identification due to their direct interpretability both in the stress–strain characteristic and on the physical basis of the Masing approach. In particular, a significant correlation has been found between three of the model parameters and the sub-grain size and dislocation density evolutions upon low-cycle fatigue loading. The adopted approach suggests potential for a future physically motivated modelling concept for the simulation of cyclic plasticity.