Continuum Model for Dislocation Dynamics

Yang Xiang
Hong Kong University of Science and Technology

2018-04-03

16:00-17:00

Room 1479, Sciences Building No. 1

Abstract

Dislocations are line defects in crystals and carriers of the plastic deformation. We present a dislocation-based three-dimensional continuum plasticity model, in which the dislocation substructures are represented by two families of dislocation density potential functions (DDPFs). The geometries and the density distribution of the dislocation ensembles are simply expressed in terms of the spatial derivatives of the DDPFs. The dynamics equations based on DDPFs are derived from the discrete dislocation dynamics, including a constitutive stress rule describing how the stress field associated with dislocation networks is determined, and a plastic flow rule governing the dynamics of the dislocation ensemble. Various short-range dislocation effects are incorporated in the continuum model.