2934 欠陥を有する中靭性配管の構造健全性評価 : その 1供用中に許容される欠陥寸法の検討

概要

論文の詳細を見る
To determine the allowable flaw sizes as acceptance standards for Class 2 and 3 piping with moderate toughness, the evaluation method by using the failure assessment curve (FAC) with the safety factor was proposed. The FAC for acceptance standards in Class 2 and 3 piping was derived from the FAC for ferritic piping in ASME Code Case N-494-3 with 2.7 in the safety factor. The allowable flaw sizes determined by the FAC for the acceptance standards were affected by the material properties represented by the basic material allowable stress, Sh. It was found that the relationship between normalized allowable flaw sizes and normalized design stress was represented as the simple equation and the effect of Sh on the allowable flaw sizes was formulated. Furthermore, the fatigue crack growth for the allowable flaw sizes calculated by using the FAC for acceptance standards was evaluated. The estimated crack growth extensions during the assumed plant-operating period were negligible. From these evaluations with the discussion of maximum value and detectability of non-destructive evaluation, the draft of allowable flaw sizes for Class 2 and 3 piping were proposed.
社団法人日本機械学会の論文
2002-09-20