On the cohesive zone model for a finite crack

The paper concentrates on the development of the crack tip model with the c ohesive zone in an infinite plate with a finite crack of mode I. The estima tion of the length of the cohesive zone and the crack tip opening displacem ent is based on the comparison of the local stress concentration according to Westergaard's theory with the cohesive stress. To calculate the cohesive stress, von Mises yield condition at the boundary of the cohesive zone is employed for plane strain and plane stress. The model of the stress distrib ution with the maximum stress within the cohesive zone is discussed. The ca lculation results of the crack tip opening displacement are compared with t he Dugdale solution for the plane stress.