OS0109 FE Analysis on Development of Twin-microstructure in Polycrystalline Mg Using Homogenized Phase-field Crystal Plasticity Model
Details
An extended model of deformation twinning based on phase-field and crystal plasticity models to represent both the rapid growth of a tip of twin-band and a large plastic deformation is developed. The phenomena of growth of twins are decoupled into two scenarios that is the lengthening and the thickening. Regarding the lengthening as a kinematic movement of twin dislocations, a convection-like term is newly added to the phase-field equation. Simple models of twin-nucleation and back-stress-like effect evolving with the twin microstructure are also presented here. To avoid the difficulties of the boundary problem and to evaluate the microscopic mechanical and morphologic response to the macroscopic mechanical load, homogenization method is applied to compute the present model via a FE analysis on polycrystalline pure Mg. The obtained results show that the strain localization occurs around the twin boundaries and the relaxation and the concentration of the stress arise respectively in the twinned phase and the matrix.
