Elastic incompatibility stresses across planar and nonplanar grain boundaries applied to ductile fracture criteria under high triaxial stress

Abstract

Grain boundary interfaces in a polycrystal under load can develop elastic incompatibilities that, in turn, can lead to stress states in the vicinity of the interface that are different from the macroscopic or applied stresses because the single crystal elastic properties are anisotropic. The focus of the present study is the unstable growth of cavities as a result of high local triaxial stress. This work is an important supplement to the authors` earlier work on ductile fracture of metals under high triaxial stress that was published in a companion journal. Naturally, their analysis will provide more general insight into the magnitude (and relevance) of elastic incompatibility stresses in materials. Aluminum, which has a relatively low anisotropy ratio, was also analyzed to contrast the behavior of silver.