Recent advances in 3-dimensional dislocation dynamics modelling were reported. A method was presented for the treatment of dislocation image stresses resulting from the presence of nearby traction-free surfaces. The image stress-field of a dislocation segment below a finite-sized free surface was obtained by the distribution of N generally prismatic rectangular or square dislocation loops padding the area (the external bounding surfaces of the simulation box). The unphysical tractions created at surface collocation points by sub-surface crystal dislocations were annulled by proper determination of the loops’ Burgers vectors. The image stresses on a dislocation segment were simply those stresses resulting from the surface loops. The accuracy could be improved by increasing the number of collocation points (i.e. surface loop density).

A Distributed-Dislocation Method for Treating Free-Surface Image Stresses in Three-Dimensional Dislocation Dynamics Simulations. L.Yan, T.A.Khraishi, Y.L.Shen, M.F.Horstemeyer: Modelling and Simulation in Materials Science and Technology, 2004, 12[4], S289-301