広幅混成Esso試験によるぜい性き裂伝播停止性能の評価に関する一考察

抄録

For the purpose to evaluate the arrestability against brittle fracture propagation, wide plate duplex Esso tests were carried out for two kinds of 9% Ni steel plates at temperatures below the liquid natural gas temperature, and for an Al-killed steel plate at a temperature below the liquid propane gas temperature.
Brittle cracks were all arrested just after passing the starter-specimen boundary under relatively high nominal stress levels, about 1/2 to 2/3 of the yield strength at ambient temperature.
A new approach to evaluate the stress intensity factors of running brittle crack was proposed on the basis of the dynamic measurement of specimen boundary displacements and the FEM stress analysis of side notched plates under prescribed displacement conditions.
The results of analysis were compared with those by conventional tangent formula or by the compliance method. The K values obtained in the present method have a tendency to saturate to a limited level for longer cracks. Some features of wide plate duplex tests were as well discussed.