On a new extended finite element method for dislocations: core enrichments

Dislocation models based on the Extended Finite Element Method (XFEM) are developed for thin shells such as carbon nanotubes (CNTs) and thin films. In shells, methods for edge dislocations, which move by glide, and prismatic dislocations, which move by climb, are described. In thin films, methods for dislocations with edge, screw and/or prismatic character are developed in three-dimensions. Singular enrichments are proposed which allow the Peach-Koehler force to be computed directly from the stress field along the dislocation line and give improved accuracy. Key words: dislocations, extended finite element method, thin films, thin shells, carbon nanotube