Simulation of Crack Tip Plasticity Using 3D Crystal Plasticity Theory

Abstract

To investigate the plasticity distribution of microstructurally small crack tip in FCC crystals, the crack tip opening displacment(CTOD), crack tip plastic zone and maximum plastic work for stationary microstructurally small cracks were calculated with the three dimensional crystal plasticity finite element theory, which was implemented in the finite element code ABAQUS with the rate dependent crystal plasticity theory code as user material subroutine. Results show that crystallographic orientation has significant influence on CTOD and maximum plastic work. The CTOD and maximum plastic work in hard orientation are larger than that in soft orientaion under the displacement controlled boundary condition, which means that crack in hard orientation is more likely to extend than that in soft orientaion. The high-angle grain boundary shows a tendency to reduce crack extension, and the dislocation ahead of the crack tip becomes blocked by high-angle grain boundary.