The effect of elastic anisotropy upon dislocation instability was investigated by using the Stroh sextic formalism. An iteration method was used to calculate the dislocation energy factor of straight dislocations and the line tension of planar curved dislocations. The iteration method provided a very efficient scheme for the numerical calculation of the energy factor and for the display of the 3-dimensional inverse energy surface. The effect of elastic anisotropy upon dislocation instability was complicated, and there was no simple way in which to extrapolate results from one material to another by, for example, using a simple multiplicative anisotropy factor. Even a small change in the elastic anisotropy could result in a completely different shape for the instability regions. The present method gave more precise results for the line tension, as compared with methods which used the sextic formalism. By examining the inverse energy surface for various Burgers vectors, the general features of dislocation instabilities in cubic elastic media were deduced. Geometrical theorems for the equilibrium of dislocation configurations of arbitrary planar shape could be generalized to the 3-dimensional situation. In the 3-dimensional case, the geometrical theorems yielded new equilibrium possibilities on the basis of the inverse energy surface.

Dislocation Instability in Anisotropic Elastic Cubic Media. L.Wang, J.Lothe: Philosophical Magazine A, 1995, 71[2], 359-87