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Azuma, Kisaburo*; Li, Y.
Journal of Pressure Vessel Technology, 144(6), p.061303_1 - 061303_13, 2022/12
Times Cited Count:1 Percentile:10.66(Engineering, Mechanical)Azuma, Kisaburo*; Yamaguchi, Yoshihito; Li, Y.
Proceedings of ASME 2021 Pressure Vessels and Piping Conference (PVP 2021) (Internet), 7 Pages, 2021/07
Azuma, Kisaburo*; Li, Y.; Xu, S.*
Journal of Pressure Vessel Technology, 142(2), p.021207_1 - 021207_10, 2020/04
Times Cited Count:1 Percentile:6.32(Engineering, Mechanical)Li, Y.; Azuma, Kisaburo*; Hasegawa, Kunio
International Journal of Pressure Vessels and Piping, 171, p.305 - 310, 2019/03
Times Cited Count:4 Percentile:32.97(Engineering, Multidisciplinary)Azuma, Kisaburo*; Li, Y.; Hasegawa, Kunio; Xu, S.*
Proceedings of 2017 ASME Pressure Vessels and Piping Conference (PVP 2017) (CD-ROM), 9 Pages, 2017/07
Azuma, Kisaburo*; Li, Y.; Hasegawa, Kunio; Shim, D. J.*
Proceedings of 2017 ASME Pressure Vessels and Piping Conference (PVP 2017) (CD-ROM), 7 Pages, 2017/07
Azuma, Kisaburo*; Li, Y.; Hasegawa, Kunio
Proceedings of 2017 ASME Pressure Vessels and Piping Conference (PVP 2017) (CD-ROM), 6 Pages, 2017/07
Azuma, Kisaburo*; Li, Y.
AIMS Materials Science, 4(2), p.328 - 339, 2017/02
Azuma, Kisaburo*; Li, Y.; Hasegawa, Kunio; Shim, D. J.*
Proceedings of 2016 ASME Pressure Vessels and Piping Conference (PVP 2016) (Internet), 7 Pages, 2016/07
Azuma, Kisaburo*; Li, Y.; Hasegawa, Kunio
Proceedings of 2016 ASME Pressure Vessels and Piping Conference (PVP 2016) (Internet), 8 Pages, 2016/07
Azuma, Kisaburo*; Li, Y.; Hasegawa, Kunio
Proceedings of 2015 ASME Pressure Vessels and Piping Conference (PVP 2015) (Internet), 5 Pages, 2015/07
Multiple flaws detected during in-service inspections are evaluated in accordance with the flaw combination rule provided in the ASME B&PV Code Section XI. The rule treats adjacent two flaws as a single combined flaw if the distance between the two flaws is equal to or less than half of the flaw depth. That is, the combination rule is consisted of flaw depth basis. However, its applicability has not been clarified systematically to the flaws with large aspect ratio, the depth of which are greater than half its length. Interactions of stress intensity factors for multiple flaws under membrane stress were investigated using finite element analyses. The numerical results suggest that the flaw combination rule might be better to use flaw length basis, instead of flaw depth.
Li, Y.; Azuma, Kisaburo*; Hasegawa, Kunio
no journal, ,
Azuma, Kisaburo*; Yamaguchi, Yoshihito; Katsuyama, Jinya; Li, Y.
no journal, ,
Lessons learned from the TEPCO Fukushima Daiichi accident indicate the importance of risk assessment for extreme external events. Seismic probabilistic risk assessments (SPRAs) are the standard methods to quantify the seismic risk of operating nuclear power plants. One of the major factors that affect the results of SPRAs is the quality of the seismic fragility analysis. Seismic fragilities represent the failure probabilities of components under earthquakes and the associated uncertainties. However, seismic fragility data of aging pipes are not readily available due to the complex behavior under seismic loading. For example, stress corrosion cracking (SCC) is one of the main material degradation phenomena of aging pipes. There is a possibility that extreme seismic loading on aging pipes may cause the propagation of cracks originally initiated by SCC. It is unclear how these crack propagations can affect the seismic fragility of the piping system. In this study, failure probabilities of carbon steel pipes and austenitic stainless steel pipes were evaluated using a probabilistic fracture mechanics code, PASCAL-SP. SCC and fatigue crack growth were considered as age-related degradations of the pipes. Comparing the failure probabilities for brand new pipes and those for aging pipes, we discussed the effects of crack growth on seismic fragilities.