低速進展き裂に関する考察 : 微細き裂のふるまい

抄録

When the tensile stress is applied to the material, the activation energy for the generation of submicrocrack decreases and the submicrocracks are thermally generated at the crack tip. The crack propagates very slowly, when the stress intensity factor of the crack is smaller than the fracture toughness of the material. Based on the postulate that the crack velocity in this regime is determined by the behavior of the submicrocrack generated at the tip of the crack, we have analyzed the experiment performed by Regel and Leksovskii in 1970. Assuming the density distribution function n(r, t) of the submicrocrack at the crack tip, we find that the stress and temperature dependence of the crack velocity agress qualitatively with their results.