A two-dimensional finite element model of the grain boundary based on thermo-mechanical strain gradient plasticity

In this work, a two-dimensional finite element model for the grain boundary flow rule is de-
veloped based on the thermo-mechanical gradient-enhanced plasticity theory. The proposed
model is temperature-dependent. A special attention is given to physical and micromechani-
cal nature of dislocation interactions in combination with thermal activation on stored and
dissipated energy. Thermodynamic conjugate microforces are decomposed into energetic and
dissipative components. Correspondingly, two different grain boundary material length sca-
les are present in the proposed model. Finally, numerical examples are solved in order to
explore characteristics of the proposed grain boundary flow rule.