Assessment of the interaction between three collinear unequal straightcracks with unified yield zones

Abstract

The Dugdale model has been modified in the paper to include the effect of linearly varying yield stress distribution. An isotropic infinite plate is considered with three collinear unequal straight cracks with coalesced yield zones. Muskhelishvili’s complex variable approach is used to solve the problem. Closed form analytical expressions for stress intensity factor and crack tip opening displacement at each crack tip are obtained when boundary of the plate is subjected to uniform stress distribution and developed yield zones are assumed variable stress distribution. Different yield zone lengths and crack tip opening displacements are observed at each crack tip. A comparative case with the solution of two equal cracks is studied to show that the problem considered in this paper is the predecessor of the two equal cracks problem.