Formation of GNDs in copper single crystal under pure bending considering planar double slip

Abstract

In the present work a finite strain non-local crystal plasticity model is implemented via UMAT in ABAQUSTM. The main objective of this work is to study the distribution of geometrically necessary dislocations in pure bending. Ashby (1969) with his hypothesis showed that the gradient of strains caused by inhomogeneous deformation plays a major role in the mechanical behavior of crystals. In this work we study the evolution of geometrically necessary dislocations (GNDs) in case of pure bending of Cu single crystals. In the present work we develop a crystal plasticity model considering the evolution of GNDs. For verification of current implementation, we have used a planar double slip model of FCC crystals derived by Asaro (1979). We show that in the absence of screw dislocations the total GNDs are in form of only edge type dislocations. The distribution of statistically stored dislocations (SSDs), GNDs and their components are in good agreement with Dai (1997).