Failure criterion for steel pipe elbows under cyclic loading

Firoozabad, Ehsan Salimi; Jeon, Bub-Gyu; Choi, Hyoung-Suk; Kim, Nam-Sik

doi:10.1016/j.engfailanal.2016.05.012

Cited by 31 publications

(10 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The proposed value of constant b in Equations (3) and (4) is 0.025 [41]. This damage index was used to express the damage to the carbon steel pipe elbows [24]. However, this damage index is less reliable for steel structures [42].…”

Section: Damage Indexmentioning

confidence: 99%

“…For Equations (5) and (6), 1.1 and 0.38 were proposed for constants c and d [42]. This damage index was used to express the seismic capacity of carbon steel pipe elbows together with the damage index of Park and Ang [24,25].…”

Section: Damage Indexmentioning

confidence: 99%

“…A study was conducted to examine the effect of the T/D ratio of the thickness (T) of a pipe elbow to its outer diameter (D) on the failure behavior [23]. The damage index of Park and Ang and that of Banon were used to quantitatively express the limit state of a pipe elbow [24]. A study was conducted to define the limit state of a pipe elbow using the damage index based on the dissipated energy [25].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

et al. 2020

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: Damage Indexmentioning

confidence: 99%

Section: Damage Indexmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…There were several recent studies both experimental and numerical addressing the problem of structural integrity and life of carbon steel elbows under severe loading conditions [6][7][8][9][10][11][12][13][14][15][16]. Fatigue life was mainly considered around 50-300 cycles, as this range is representative of a typical earthquake loading.…”

Section: Introductionmentioning

confidence: 99%

Low Cycle Fatigue Behavior of Elbows with Local Wall Thinning

Harun¹,

Mohammad²,

Kotousov

2020

Metals

View full text Add to dashboard Cite

There have been a number of studies concerning the integrity of high-strength carbon steel pipe elbows weakened by local pipe wall thinning, the latter can be typically caused by flow accelerated erosion/corrosion. In particular, the focus of several recent studies was on low cycle fatigue behavior of damaged elbows, mainly, in relation to strength and integrity of piping systems of nuclear power plants subjected to extreme loading conditions, such as earthquake or shutdown. The current paper largely adopts the existing methodology, which was previously developed, and extends it to copper-nickel elbows, which are widely utilized in civil infrastructure in seismically active regions. FE (finite element) studies along with a full-scale testing program were conducted and the outcomes are summarized in this article. The overall conclusion is that the tested elbows with various severity of local wall thinning, which were artificially introduced at different locations, demonstrate a strong resistance against low cycle fatigue loading. In addition, elbows with wall thinning defects possess a significant safety margin against seismic loading. These research outcomes will contribute to the development of strength evaluation procedures and will help to develop more effective maintenance procedures for piping equipment utilized in civil infrastructure.

show abstract

“…[4][5][6][7] However, bends and elbows over time are subjected to the flow accelerated corrosion leading to the localised wall thinning. [8][9][10] Therefore, it is important to understand the effect of these structural defects on the strength in order to maintain the safety and integrity of hazardous structures. This problem was also emphasised during investigations of the integrity and residual strength of piping containing wall thinning defects after recent powerful earthquakes in Japan.…”

Section: Introductionmentioning

confidence: 99%

Effect of wall thinning on deformation and failure of copper‐nickel alloy elbows subjected to low cycle fatigue

Harun

Mohammad

Kotousov

2019

Mat Design & Process Comms

View full text Add to dashboard Cite

Various industrial standards and safety regulations specify the minim number of cycles, which pressure equipment must tolerate during a single seismic event. The compliance with these standards and regulations is necessary in order to ensure safety and strength of critical structural components, eg, pressure pipe system of the primary coolant loop of nuclear reactors or condensed water supply of large hospitals or other large facilities. However, the strength can degrade with time due to flow accelerated corrosion causing wall thinning. Pipe bends are particularly susceptible to the localised corrosion, and, therefore, these structural elements need a special consideration. The current paper studies the effect of localised corrosion on low cycle fatigue behaviour of a copper-nickel elbows using experiment and finite element method (FEM). The outcomes of the study demonstrate a quite low reduction of low cycle fatigue life even at severe local wall thinning at different locations.

show abstract

Failure criterion for steel pipe elbows under cyclic loading

Cited by 31 publications

References 28 publications

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

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

Low Cycle Fatigue Behavior of Elbows with Local Wall Thinning

Effect of wall thinning on deformation and failure of copper‐nickel alloy elbows subjected to low cycle fatigue

Contact Info

Product

Resources

About