Failure criteria of a carbon steel pipe elbow for low-cycle fatigue using the damage index

2020 ◽  
Vol 153 ◽  
pp. 106800
Author(s):  
Sung-Wan Kim ◽  
Sung-Jin Chang ◽  
Dong-Uk Park ◽  
Bub-Gyu Jeon
Keyword(s):  
Carbon Steel ◽  
Low Cycle Fatigue ◽  
Damage Index ◽  
Failure Criteria ◽  
Steel Pipe ◽  
Cycle Fatigue ◽  
Pipe Elbow

scholarly journals Evaluation of the Limit State of a Six-Inch Carbon Steel Pipe Elbow in Base-Isolated Nuclear Power Plants

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8400
Author(s):  
Sung-Wan Kim ◽  
Da-Woon Yun ◽  
Bub-Gyu Jeon ◽  
Dae-Gi Hahm ◽  
Min-Kyu Kim
Keyword(s):  
Carbon Steel ◽  
Nuclear Power ◽  
Power Plants ◽  
Base Isolation ◽  
Low Cycle Fatigue ◽  
Limit State ◽  
Steel Pipe ◽  
Cycle Fatigue ◽  
Pipe Elbow ◽  
Isolation Systems

The installation of base isolation systems in nuclear power plants can improve their safety from seismic loads. However, nuclear power plants with base isolation systems experience greater displacement as they handle seismic loads. The increase in relative displacement is caused by the installed base isolation systems, which increase the seismic risk of the interface piping system. It was found that the failure mode of the interface piping system was low-cycle fatigue failure accompanied by ratcheting, and the fittings (elbows and tees) failed due to the concentration of nonlinear behavior. Therefore, in this study, the limit state was defined as leakage, and an in-plane cyclic loading test was conducted in order to quantitatively express the failure criteria for the SCH40 6-inch carbon steel pipe elbow due to low-cycle fatigue failure. The leakage line and low-cycle fatigue curves of the SCH40 6-inch carbon steel pipe elbow were presented based on the test results. In addition, the limit state was quantitatively expressed using the damage index, based on the combination of ductility and energy dissipation. The average values of the damage index for the 6-inch pipe elbow calculated using the force−displacement (P–D) and moment−relative deformation angle (M–R) relationships were found to be 10.91 and 11.27, respectively.

scholarly journals Quantitative Limit State Assessment of a 3-Inch Carbon Steel Pipe Tee in a Nuclear Power Plant Using a Damage Index

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6395
Author(s):  
Sung-Wan Kim ◽  
Da-Woon Yun ◽  
Sung-Jin Chang ◽  
Dong-Uk Park ◽  
Bub-Gyu Jeon
Keyword(s):  
Carbon Steel ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Damage Index ◽  
Failure Criteria ◽  
Relative Displacement ◽  
Steel Pipe ◽  
Piping System ◽  
Piping Systems

Seismic motions are likely to cause large displacements in nuclear power plants because the main mode of their piping systems is dominated by the low-frequency region. Additionally, large relative displacement may occur in the piping systems because their supports are installed in several places, and each support is subjected to different seismic motions. Therefore, to assess the seismic performance of a piping system, the relative displacement repeated by seismic motions must be considered. In this study, in-plane cyclic loading tests were conducted under various constant amplitudes using test specimens composed of SCH 40 3-inch pipes and a tee in the piping system of a nuclear power plant. Additionally, an attempt was made to quantitatively express the failure criteria using a damage index based on the dissipated energy that used the force–displacement and moment–deformation angle relationships. The failure mode was defined as the leakage caused by a through-wall crack, and the failure criteria were compared and analyzed using the damage index of Park and Ang and that of Banon. Additionally, the method of defining the yield point required to calculate the damage index was examined. It was confirmed that the failure criteria of the SCH 40 3-inch carbon steel pipe tee can be effectively expressed using the damage index.

Low cycle fatigue and ductile fracture for Japanese carbon steel piping under dynamic loadings

1994 ◽  
Vol 153 (1) ◽  
pp. 57-69 ◽  
Author(s):  
Naoki Miura ◽  
Terutaka Fujioka ◽  
Koichi Kashima ◽  
Satoshi Kanno ◽  
Makoto Hayashi ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Ductile Fracture ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Dynamic Loadings ◽  
Steel Piping

Using CFRP to Repair the Steel Pipe with Fatigue Cracks

2010 ◽  
Vol 146-147 ◽  
pp. 1086-1089 ◽  
Author(s):  
Hong Tao Zhang ◽  
Xiao Xiang Xue ◽  
Yan Zheng ◽  
Peng Feng
Keyword(s):  
Low Cycle Fatigue ◽  
Fatigue Cracks ◽  
Fiber Reinforced Polymer ◽  
Steel Pipe ◽  
Carbon Fiber Reinforced Polymer ◽  
Cycle Fatigue ◽  
Safe Operation ◽  
Reinforced Polymer ◽  
Pressure Pipeline ◽  
Crack Defect

This paper provides a new method to repair the steel pipe with fatigue cracks by using carbon fiber reinforced polymer (CFRP). Cracks may arise in Pressure pipeline in service because of low cycle fatigue. Crack defect is the biggest problem, because crack will gradually propagate and seriously threaten the safe operation of pipeline. This paper provides a repair and calculation method for pressure pipeline with fatigue cracks, and some specific engineering cases are given based on this method.

scholarly journals Effect of hydrogen absorption on strain-induced low-cycle fatigue of low carbon steel

2010 ◽  
Vol 2 (1) ◽  
pp. 555-561 ◽  
Author(s):  
Y. Tsuchida ◽  
T. Watanabe ◽  
T. Kato ◽  
T. Seto
Keyword(s):  
Carbon Steel ◽  
Hydrogen Absorption ◽  
Low Cycle Fatigue ◽  
Low Carbon Steel ◽  
Cycle Fatigue ◽  
Low Carbon

Effect of Hydrogen on Low Cycle Fatigue of S45C Carbon Steel under Non-proportional loading

2016 ◽  
Vol 2016 (0) ◽  
pp. OS16-08
Author(s):  
Takaei YAMAMOTO ◽  
Masanori MITSUNE ◽  
Takeshi TAKEMURA ◽  
Noriko TSUTSUMI ◽  
Takamoto ITOH
Keyword(s):  
Carbon Steel ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Proportional Loading
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