Fracture instability of notched cracked plates characterized by the strain energy density theory

Abstract

The fracture instability of a mechanical system is analyzed by the strain energy density theory. The local relative minima of the strain energy density function d W/d V referred to local coordinate systems at each point of the body are distinguished from the global minimum of d W/d V, G, which is referred to a fixed global coordinate system. Failure by fracture starts from the maximum of the local minima of d W/d V, L, and passes from point G. The distance l between L and G along the fracture trajectory is introduced as a length parameter to characterized the fracture instability of the system. Numerical results are obtained and discussed for a cracked plate with two symmetrical notches subjected to a monotonically rising tensile stress perpendicular to the crack axis.