Failure Criteria of a 6-Inch Carbon Steel Pipe Elbow According to Deformation Angle Measurement Positions

2022 ◽  
Vol 26 (1) ◽  
pp. 13-22
2020 ◽  
Vol 153 ◽  
pp. 106800
Author(s):  
Sung-Wan Kim ◽  
Sung-Jin Chang ◽  
Dong-Uk Park ◽  
Bub-Gyu Jeon

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8400
Author(s):  
Sung-Wan Kim ◽  
Da-Woon Yun ◽  
Bub-Gyu Jeon ◽  
Dae-Gi Hahm ◽  
Min-Kyu Kim

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.


Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6395
Author(s):  
Sung-Wan Kim ◽  
Da-Woon Yun ◽  
Sung-Jin Chang ◽  
Dong-Uk Park ◽  
Bub-Gyu Jeon

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.


2018 ◽  
Vol 13 ◽  
pp. 2137-2142 ◽  
Author(s):  
M. Amara ◽  
B.G.N. Muthanna ◽  
M. Tahar Abbes ◽  
M. Hadj Meliani

2018 ◽  
Vol 7 (2.14) ◽  
pp. 171
Author(s):  
Ahmed N. Abdalla ◽  
Kharudin Ali ◽  
Johnny Koh Siaw Paw ◽  
Chong Kok Hen ◽  
Tan Jian Ding ◽  
...  

AC excitation signal is most widely used in Non Destructed Testing (NDT) devices for Piezoelectric Technique (PZT) method in an inspec-tion. This paper is presenting the application of piezoelectric with end to end method for defect identification for Carbon Steel Pipe (CSP) where the frequency is used around 1kHz until 6kHz for standard pipe, transverse defect pipe, longitudinal defect pipe and hole defect pipe. From here, the identification of defect signal by based on the signal pick value and different pick signal between ordinary pipe (without defect) and defects pipe are analysis. The result shows that the standard pipe will give the high amplitude of signal compare the defect pipe by based on the type of defect, size of defect and depth of defect. Findings from the comparative study, validate the application of piezoelec-tric show that the different amplitude of the signal is directly proportional with excitation signal frequency and through the experiment, the longitudinal defect is contributed the different high signal until 79.7% compared to the hole and transverse defect 74.4 %.


2014 ◽  
Vol 1065-1069 ◽  
pp. 1349-1353
Author(s):  
Zhen Kai Duan ◽  
Rui Wang

Concrete-Filled Steel Tube with high capacity, good ductility and toughness, convenient construction, good fire resistance and other advantages. Currently[1] . Concrete-Filled Steel Tube structure has been widely used in the basic components and the overall structure of behavioral research has made many achievements. There are many advantages of concrete pipe above, but it also has fatal flaws, Stainless steel steel that is the difference[2]. The stainless steel has a beautiful appearance, durability, corrosion resistance, low maintenance costs, good fire resistance and other advantages. New stainless steel pipe concrete structure has both ordinary steel concrete good mechanical properties and excellent durability of stainless steel, can be widely used in buildings and bridges of the marine environment as well as some of the high durability and aesthetic requirements important building structures. Based on the outer stainless steel hollow sandwich - the carbon steel pipe shaft of light pressure test concrete results of load and displacement of the structure, variation of load and strain, and the impact of the empty heart of these parameters.


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