Modified Kocks-Mecking-Estrin Model to Account Nonlinear Strain Hardening

The dislocation density-based model after Kocks-Mecking-Estrin (KME) is widely used to characterize the thermally activated plastic deformation and dislocation kinetics. According to the model, the slope of the stress-strain curve decreases linearly with stress, which contradicts the experimental observation. In the current study, the evolution of dislocation density in the model is generalized to account for the nonlinearity of the slope.