INTERACTION OF PREFRACTURE ZONES IN A ROD FUEL ELEMENT
We study the plane fracture mechanics problem for interaction of arbitrary number of pre-fracture zones in a rod fuel element. During operation of the rod fuel element various damages, particularly cracks formation, are possible. We consider the problem for rod fuel element with a protective coating when with increasing of internal heat source intensity in the element are forming domains of higher stresses. The domains of higher stresses will contribute to the emergence of zones of weakened interparticle bonds of materials (pre-fracture zones). Interaction of prefracture zones faces is modeled by bonds between the faces having a given deformation diagram. The problem of the prefracture zones interaction is reduced to solving of a system of nonlinear singular integral equations. From solution of this equations system are found the normal and tangential forces in the zones of crack nucleation. Condition of cracking is formed based on the criterion of limit traction of the material bonds.