THE DEFORMATION AND FRACTURE OF CONSTRAINED METAL SHEETS

A brittle solid can be toughened by dispersing ductile inclusions in it. The degree of toughening depends on the properties, volume fraction and size of the ductile inclusions and on the strength of the interface between inclusion and matrix. Experiments and models are described which quantify the influence of interface strength. The experiments use a sandwich of lead bonded between two glass plates, in such a way that debonding can be controlled. Cracks are introduced into the glass, and the behaviour of the lead at and near the crack tip is examined. The way in which debond and crack-orientation influence the work of fracture is explored.