An interfacial energy incorporated couple stress crystal plasticity and the finite element simulation of grain subdivision

A couple stress crystal plasticity formulation that incorporates interfacial couple stress energy was proposed in terms of the virtual work-rate principle for finite element method. By applying the assumed constitutive models of couple stress at the grain boundary as well as the grain interior, finite element simulations were conducted for various crystal models, with different grain subdivision models to examine how plastic deformation work is affected by grain subdivision from the interfacial couple stress energy effect.Finite element simulation results showed that the amount of predicted plastic deformation work depends on grain subdivision, and that the amount of work can be minimized for a particular grain subdivision. We inferred from the simulation results that actual grain subdivision might correspond to the minimum amount of plastic deformation work and, if this correlation is validated, actual grain subdivision might be predicted based on the interfacial energy incorporated couple stress crystal plasticity.