An isotropic disk of radius R, loaded on the contour by two concentrated forces P, apllied to the points z1 = R and z2 = −R, is considered. A model of cracking in a circular disk, based on consideration of fracture process zone, is proposed. It is assumed that the fracture process zone is a finite length layer, containing material with partially broken bonds between individual structural elements. Equations for determination of the external load critical value at which the crack is observed are obtained.
