段違い複数欠陥円筒に対する破壊試験および解析評価の検討

抄録

An applicability of flaw characterization rules provided by codes, such as JSME fitness-for-service code, to ductile fracture of non-aligned multiple flaws remains an issue of structural integrity evaluation. Hence, this paper deals with investigating evaluation of collapse load of a pipe with non-aligned flaws subjected to bending moment by experiments and analytical approach. Through-wall non-aligned flaws were introduced to 4-inch pipes made of austenitic stainless steel by electric discharge machining. 4-point bending tests of the pipe were conducted to observe collapse behavior and obtain load-displacement relationships. Flaw interactions depending on distances between two flaws were observed from the test results. Finite element models on the basis of the test conditions were generated and elasto-plastic analysis considering non-linear geometry were conducted. Twice elastic slope method was applied to the analysis results to estimate collapse loads. The estimated collapse loads can represent tendency of the test results and derive conservative results.