Crack Characteristic Model of Metal Matrix Induced by Dispersion Fuel Particle Cracking

Metal matrix dispersion fuel will be vitiated in the form of surface blistering under special conditions. Fuel particle cracking is the precondition of metal matrix cracking, and surface blistering will occur only when the metal matrix is cracked. After fuel particle cracking, the crack characteristics, such as crack width and plastic zone length, determine the cracking behavior of metal matrix. Based on the elastic-plastic fracture mechanics and stress equilibrium, the crack characteristic model of metal matrix induced by dispersion fuel particle cracking was established. The calculation results show that the crack opening displacement increases with the annealing temperature and the burnup. The length of plastic zone at the crack tip is mainly related to annealing temperature. The calculated results of crack opening displacement and plastic zone length are in good agreement with the experimental data, verifying the validity of the crack characteristic model of metal matrix.