Strength and Specific Fracture Energy of Metals Subjected to a Thermal Shock

Time dependences of spalling strength and critical specific fracture energy of some metals under a thermal shock initiated by x‐rays of a nuclear explosion are obtained. Under thermal‐shock conditions, the durability of metals decreases exponentially as the amplitude of the fracture stress increases. The critical specific fracture energy of metals subjected to a thermal shock increases with the duration of tensile stresses. Using an example of cones, conical shells, disks, and rods, it is shown that the geometric factor should be taken into account, which can reduce the fracture threshold and increase the degree of fracture of an object subjected to a thermal shock. This is a result of stress cumulation, occurrence of cumulative ejection of the material, and stability loss due to the action of powerful energy fluxes.