On the existence ofr⁻ⁿsingular fields at a bimaterial wedge or triple junction

Abstract Second-order singularities, that is r −2 stress fields, such as a concentrated couple, a centre of dilatation, a dipole of dislocations or a centre of shear, exist in an infinite material or inside a finite domain but may not exist when the point of application approaches the vertex of a wedge, an embedded wedge or a triple junction. The solutions that can be obtained on the basis of the Michell stress function are examined.