Creep failure in a threshold-activated dynamics: Role of temperature during a subcritical loading

Abstract

Creep is a time-dependent deformation of solids at relatively low stresses, leading to the breakdown with time. Here we propose a simple model for creep failure of disordered solids in which temperature and stress are controllable. Despite its simplicity, this model can reproduce most experimental observations: Distribution of the creep lifetime obeys the log-normal distribution, and the average creep lifetime decays in a scale-free manner with the increasing stress. Finally, to characterize the failure abruptness, the average breakdown frequency is introduced as an order parameter, which exhibits a series of jumps with varying temperature. Finite-size scaling holds for these jumps, implying the existence of nonequilibrium transitions.