検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年
検索結果: 5 件中 1件目~5件目を表示
  • 1

発表形式

Initialising ...

選択項目を絞り込む

掲載資料名

Initialising ...

発表会議名

Initialising ...

筆頭著者名

Initialising ...

キーワード

Initialising ...

使用言語

Initialising ...

発行年

Initialising ...

開催年

Initialising ...

選択した検索結果をダウンロード

論文

Plastic collapse stresses based on flaw combination rules for pipes containing two circumferential similar flaws

長谷川 邦夫; Li, Y.; Kim, Y.-J.*; Lacroix, V.*; Strnadel, B.*

Journal of Pressure Vessel Technology, 141(3), p.031201_1 - 031201_5, 2019/06

 被引用回数:0 パーセンタイル:100(Engineering, Mechanical)

2個の欠陥が近接して存在する場合は、これらの欠陥は1つの欠陥に合体される。この合体評価は多くの国の維持規格に採用されているが、具体的な合体クライテリアは異なっている。一方、2個の周方向欠陥を有するステンレス鋼配管の曲げ試験が行われており、塑性崩壊荷重は求められている。また、解析的な式も導かれている。本研究では、これらの実験と解析結果から得られる塑性崩壊応力を合体クライテリアから導かれる塑性崩壊応力と比較した。その結果、合体クライテリアを用いた塑性崩壊応力は、実験や解析結果と極めて異なることが分かった。

論文

Remaining fatigue lives of similar surface flaws in accordance with combination rules

Lu, K.; Li, Y.; 長谷川 邦夫*; Lacroix, V.*

Journal of Pressure Vessel Technology, 139(2), p.021407_1 - 021407_6, 2017/04

 被引用回数:1 パーセンタイル:84.43(Engineering, Mechanical)

When multiple flaws are detected in structural components, remaining lives of the components are estimated by fatigue flaw growth calculations using combination rules in fitness-for-service (FFS) codes. A lot of FFS codes provide combination rules for multiple flaws, however, these combination rules are significantly different among the various FFS codes. Fatigue flaw growth for two similar adjacent surface flaws in a pipe subjected to cyclic tensile stress were obtained by numerical calculations using these different combination rules. In addition, fatigue lives taking into account interaction effect between the two similar flaws were conducted by extended finite element method (X-FEM). As the calculation results, it is found that the fatigue lives calculated by the X-FEM are close to those by the ASME Code. Finally, it is worth noticing that the combination rule provided by the ASME Code is appropriate for fatigue flaw growth calculations.

論文

Fatigue crack growth calculations for two adjacent surface cracks using combination rules in fitness-for-service codes

Lu, K.; Li, Y.

AIMS Materials Science, 4(2), p.439 - 451, 2017/03

If multiple discrete cracks are detected in structural components, the combination rules provided in fitness-for-service (FFS) codes are employed to estimate the remaining lives of the components by fatigue crack growth (FCG) calculations. However, the specific criteria for combination rules prescribed by various FFS codes are different. This paper presents FCG calculations for two adjacent surface cracks in a flat plate using different combination criteria. Three different crack aspect ratios of 0.05, 0.15 and 0.5, and a nominal distance of 5 mm between the two cracks are investigated in the calculations. The results show that the FCG behaviors obtained by various codes are significantly different. In addition, the combination process of the two cracks is found to affect the crack shape development remarkably.

論文

Fatigue lives of multiple flaws in accordance with combination rule

Lu, K.; Li, Y.; 長谷川 邦夫; Lacroix, V.*

Proceedings of 2016 ASME Pressure Vessels and Piping Conference (PVP 2016) (Internet), 7 Pages, 2016/07

When multiple flaws are detected in structural components, remaining lives of the components are estimated by fatigue flaw growth calculations using combination rules in fitness-for-service codes. ASME, BS7910 and FITNET Codes provide different combination rules. Fatigue flaw growth for adjacent surface flaws in a pipe subjected to cyclic tensile stress were obtained by numerical calculations using these different combination rules. In addition, fatigue lives taking into account interaction effect between the two flaws were conducted by extended finite element method (X-FEM). As the calculation results, it is found that the fatigue lives calculated by the X-FEM are close to those by the ASME Code. Finally, it is worth noticing that the combination rule provided by the ASME Code is appropriate for fatigue flaw growth calculations.

口頭

Fatigue crack growth behaviour for adjacent two surface flaws in accordance with combination rules

Lu, K.; Li, Y.; 長谷川 邦夫*; Lacroix, V.*

no journal, , 

原子力機器等の構造物に、経年事象による複数亀裂の発生があり得る。現行の構造物の健全性評価では、維持規格に規定されている複数亀裂の合体基準に従った疲労亀裂等の進展計算を行い、構造物の疲労寿命を評価している。しかし、各国の維持規格は異なる合体基準が用いられている。本論文では、2個の同一平面の表面亀裂を有する配管の疲労亀裂進展解析を行い、複数の合体基準を用いて配管の疲労寿命を求めた。あわせて、亀裂間の応力拡大係数の干渉効果を考慮した拡張有限要素法による疲労寿命を求めた。その結果、国内の維持規格に従って計算した疲労寿命は拡張有限要素法で得られた結果に近く、一部の国の合体基準は過度の保守性が含まれていることを明らかにした。

5 件中 1件目~5件目を表示
  • 1