延性不安定破壊の破壊力学的検討およびその配管系の安全性評価への適用

概要

論文の詳細を見る
One of the most serious accidents which might possibly occur in piping systems is the sudden severing of pipe by tearing instability. Among safety assessment methods against this kind of fracture, the tearing instability theory based on the J-integral resistance curve is believed to be the most attractive one, because it can take account of compliance which is one of the important factors for tearing instability. This paper firstly presents tearing instability experiments using center and double-edge notched specimens. Load was applied to the specimens through a pipe tab with high compliance. Tearing instability occurred in all specimens after maximum load. The instability was predicted to take place when the value of T_<appl>, which is related to specimen configuration, compliance and other parameters, exceeded that of T_<mat>, which is concerned with the slope of J-integral resistance curve. The predicted instability point for each test compared well with the experimental point. Next, the paper proposed a formula of calculating the value of T_<appl> for a circumferential crack which lies in piping systems. The formula had been limitted to the simplest configuration of piping system, i. e. a straight pipe subjected to bending moment at both ends, because actual piping systems have three-dimensional structures, and that made it difficult to obtain the formula which took account of the overall compliance quantitatively. The paper showed that the problem for actual three-dimensional piping systems could be reduced to the equivalent problem of a straight pipe subjected to bending, where the equivalent length of straight pipe could be calculated from conventional finite element analysis of the piping system. The proposed formula can be used for the safety assessment of piping systems against tearing instability.
社団法人日本材料学会の論文
1982-05-15

延性不安定破壊の破壊力学的検討およびその配管系の安全性評価への適用

スポンサーリンク

概要

著者

関連論文

スポンサーリンク