段違い複数欠陥に対する破壊評価手法の開発

抄録

Fracture tests of a flat plate were conducted to develop assessment methodology of ductile fracture of non-aligned flaws. Although JSME fitness-for-service code provides flaw characterization rules for multiple flaws, it seems to be determined based on the linear fracture mechanics. Thus, the development of the assessment methodology for a component with non-aligned flaws made of high toughness materials remains an issue of structural integrity. Hence, this paper deals with development of the assessment methodology of non-aligned flaws on the basis of experimental results. Through-wall non-aligned flaws were introduced to flat plates made of austenitic stainless steel by electric discharge machining. Tensile tests of the flat plate were conducted to observe collapse behavior and obtain load-displacement relationships. The previous and present experimental results revealed the flaw lengths and a distance between flawed cross sections are representative parameters of the ductile fracture. The evaluation results using the representative parameters corresponded with the experimental results and the assessment procedure was proposed in this paper.