ELASTOPLASTIC FRACTURE OF A PLATE WITH TWO EDGE CRACKS

Abstract

The strength of a rectangular plate with two opening-mode (mode I) edge cracks was studied using the Neuber–Novozhilov approach and a modified Leonov–Panasyuk–Dugdale model with a nonzero prefracture zone. A coupled discrete-integral fracture criterion is used since the stress field in the vicinity of the crack tip has a singularity. The ultimate strain fracture criterion is satisfied at the real crack tip, and the normal stress criterion is satisfied at the model crack tip. The constitutive equations of the analytical model are analyzed. Simple formulas for the fracture load are derived for quasi-brittle and quasi-ductile fracture. Plate fracture curves are plotted for a plane stressed state.