A study of effects of pipe geometry on FAD curves for austenitic stainless steel and ferritic steel piping materials
- Battelle, Columbus, OH (United States)
- Oak Ridge National Lab., TN (United States)
- Babcock and Wilcox, Alliance, OH (United States)
A comprehensive study of failure assessment diagrams for circumferentially surface-cracked austenitic stainless and ferritic steel pipes was conducted with the use of the finite element method (FEM). While the majority of the analyses were conducted using the line-spring/shell finite element method, some three-dimensional finite element analyses, conducted independently, are also reported in this paper. Comparison of the predictions of the line-spring/shell and three-dimensional analyses reinforce the validity of the former approach for surface-cracked pipes. The results indicated that the ASME Code Case N-494-2 applicable for ferritic steel piping appears reasonably conservative even for pipes with mean radius-to-wall thickness ratios of 20, whereas the results showed that the newly adopted Code Case N-494-3 for austenitic stainless steel piping requires a limit for pipe with mean radius-to-wall thickness ratios larger than 15. For consistency, the limitation of R{sub m}/t {le} 15 was incorporated in the approved final version of Code Case N-494-3, and was incorporated in Code Case N-494-2 as well. Because these Code cases are applicable only to Class 1 primary nuclear piping, which typically has values of R{sub m}/t {le} 15, this is not a significant limitation. It was also shown that the choice of definitions of membrane and bending stresses as well as the choice of F{sub 1} function values in calculating the elastic part of the J integral have a profound effect on the resulting FAD curves.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 616379
- Journal Information:
- Journal of Pressure Vessel Technology, Journal Name: Journal of Pressure Vessel Technology Journal Issue: 1 Vol. 120; ISSN JPVTAS; ISSN 0094-9930
- Country of Publication:
- United States
- Language:
- English
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