Crystal plasticity finite element simulation of crack growth in single crystals

A new method for 3D simulation of crack growth in single crystals is proposed. From Crystal Plasticity Finite Element (CPFE) computations of a pre-cracked single crystal, a damage indicator based on the accumulated slip, the resolved shear stress and the normal stress on each slip system is calculated at each integration point and for every time increment. The crack growth direction is then determined in 3D by analysing the damage indicator in the region around the crack front. The crack is extended via remeshing at each propagation event. At this point the CPFE computation is restarted, using the new crack configuration. Two examples in BCC single crystals featuring different crystal orientations and slip systems show the crack propagation simulations under monotonic loading over distances comparable to the crystal size and with non-regular crack shape and path.