rod fuel element, a protective cover, system of rectilinear cracks, end zones with bonds between faces, cohesive forces.

The plane problem of mechanics of fracture for rod fuel element which sections are occupied with area in the form of a circle of radius R1 and weakened by system of any way placed rectilinear cracks with end zones of the weakened interpartial bonds of a material is considered. Interaction of face in end zones is modelled by introduction of bonds (cohesive forces) between faces of cracks in end zones. The system “fuel element and a protective cover” is considered at the established mode. The fracture model fuel element, based on consideration of a zone of process of fracture near to top of a crack with end zones is offered. It is accepted that the zone of process of fracture represents a layer of finite length, with a material partially broken bonds between its separate structural elements (end zone). Definition of the unknown parametres characterising development of cracks, is reduced to the system singular integrated equations with a kernel of type of Koshi. By means of procedure algebraization the system of the integrated equations is reduced to system of the nonlinear algebraic equations which dares a method consecutive approximations. From the solution of this system of the equations are normal and tangents the tractions in end zones of prefracture. The analysis of limiting balance fuel element is carried out on the basis of deformation criterion of fracture.

Ismayilova, Rena Ashraf qizi Postgraduate student, Institute of Mathematics and Mechanics NAN of Azerbaijan