Seismic Proving Test of Eroded Piping: Status of Eroded Piping Component and System Test

Namita, Yoshio; Suzuki, Koichi; Abe, Hiroshi; Ichihashi, I.; Shiratori, Masaki; Tai, Koichi; Iwata, Koichiro; Nebu, Akira

doi:10.1115/pvp2003-2097

Cited by 7 publications

(4 citation statements)

References 1 publication

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“…It is known that ratchet strain is difficult to simulate, but the strain range could be simulated precisely by FEM. For evaluating the fatigue evaluation more reasonably, it could be proposed that calculating the strain range by FEM and evaluating the fatigue with NUPEC prediction curve shown in figure 19 [8]. The prediction curve was defined from the pipe and pipe fittings element test results under the hoop stress level was almost 1.0S m [6] [7] [8].…”

Section: Resultsmentioning

confidence: 99%

“…PFDRP by EPRI [4] is well known as successful research in the United States. NUPEC in Japan performed research programs of "Seismic Proving Test of Ultimate Piping Strength" [6], [7] and "Seismic Proving Test of Eroded Piping" [8] in Japan. The authors also investigated about failure behavior of piping under seismic excitation, "Aged Piping (AP) research", in which many shaking table tests and piping element tests were performed [10], [11].…”

Section: Typical Failure Of Elbowmentioning

confidence: 99%

“…Regarding to pipe, pipe fittings and piping system, many researches were performed to verify the ultimate strength against earthquake since the latter half of 1980s [4], [5], [6], [7], [8]. And they show that most of the failures by seismic excitation were low cycle fatigue, except for only a few case of collapse failure.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

J101013 Consideration on Seismic Design Margin of Elbow in Piping

Otani¹,

Izumi²,

Takada³

et al. 2011

The Proceedings of Mechanical Engineering Congress, Japan

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Elbow is an essential element for three dimensionally arranged piping and it is actually used in most kinds of plants. Many great researches on the flexibility and stress intensity regarding elbow elements have been performed. Moreover, we can greatly benefit from the design code where elbow elements are specified. Our research group also started a research on ultimate strength of piping systems containing elbows in 1997 and we have performed several kinds of elbow element tests and shaking table tests. All experimental results have shown that the failure loads are far higher than those described by the design criteria. The authors have confirmed that the seismic design margin is extremely conservative. In this paper, the results of shaking table tests of piping, elbow element experiments and the stress calculation for those experiments based on design code are described, their results are compared with the seismic design criteria, and the margin is discussed. The authors point out the necessity of a new design code on the basis of the detail analysis and strain criteria in order to describe more appropriate and reasonable seismic design margin of the piping.

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Section: Resultsmentioning

confidence: 99%

Section: Typical Failure Of Elbowmentioning

confidence: 99%

See 1 more Smart Citation

J101013 Consideration on Seismic Design Margin of Elbow in Piping

Otani¹,

Izumi²,

Takada³

et al. 2011

The Proceedings of Mechanical Engineering Congress, Japan

View full text Add to dashboard Cite

show abstract

“…Also, structural analysis error by difference of geometry between the test specimen and the analysis model includes in this prediction results. Moreover, it was reported that fatigue lives of piping components decrease by tri-axial effect compared to fatigue lives of the material (Namita, 2003). Because there are many factors for error like above, it is difficult to predict the fatigue life of the structure.…”

Section: Prediction Of Fatigue Lifementioning

confidence: 99%

Investigation on ultimate strength of thin wall tee pipe for sodium cooled fast reactor under seismic loading

Watakabe

Tsukimori

Otani

et al. 2016

Mechanical Engineering Journal

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It is important to investigate the failure mode and ultimate strength of piping components in order to evaluate the seismic integrity of piping. Many failure tests of thick wall and high pressure piping for Light Water Reactors (LWRs) have been conducted, and the results suggest that the failure mode that should be considered in the design of a thick wall piping for LWRs under seismic loading is low cycle fatigue. On the other hand, Sodium cooled Fast Reactors (SFRs) is thin wall when compared to LWRs piping. Failure tests of a thin wall piping are necessary because past failure tests for LWRs piping are not enough to discuss failure behavior of a thin wall piping. Therefore, this present work investigated the failure mode and the ultimate strength of thin wall tees.

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Pressure stresses generated due to supersonic steam jet induced hydrodynamic instabilities

Khan

Sanaullah

Takriff

et al. 2016

Chemical Engineering Science

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Hydrodynamic instabilities emerged both in axial as well as radial direction. Instabilities created at the steam water interface and propagated towards the walls. These instabilities produce pressure stresses in a non-deterministic way. Both hydrodynamic instabilities and their induced stresses are asymmetric in nature. The strength of these instabilities varies along radial as well as axial directions. a r t i c l e i n f o a b s t r a c tThe phenomenon that involves direct contact of steam with water is called Direct Contact Condensation (DCC). This phenomenon has been observed/prevailed in most of the power and process industries. The phenomenon of direct contact condensation involves heat, mass and momentum transfer across the highly fluctuating interface between steam jet and surrounding water giving this process an intricate nature to be studied. More recently the observation of hydrodynamic instabilities at the interface between supersonic steam jet and water has given a new facet to the study of DCC. In the current study the equivalent von-Mises Stress, equivalent elastic strain and total deformation in the Perspex vessel that has been incurred due to the pressure stresses has been studied. These pressure stresses have been generated due to the condensing supersonic steam jet induced hydrodynamic instabilities. It has been investigated first by experimentally observing the temperature fluctuations in axial and radial directions across supersonic steam jet which actually depicts these instabilities. Then Direct Contact Condensation (DCC) model has been used to conduct the CFD study using a commercial code Ansys s . Accompanied with this a mock up study has been done in which the pressure loads computed using DCC model have been coupled to the Perspex vessel structure using one way Fluid Structure Interaction (FSI) analysis in Ansys s to compute the true scale equivalent von-Mises Stress, equivalent elastic strain and total deformation generated by hydrodynamic instabilities induced pressure stresses. On true scale, hundreds of Pico scale deformation has been computed in the Perspex vessel confinement.

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Seismic Proving Test of Eroded Piping: Status of Eroded Piping Component and System Test

Cited by 7 publications

References 1 publication

J101013 Consideration on Seismic Design Margin of Elbow in Piping

J101013 Consideration on Seismic Design Margin of Elbow in Piping

Investigation on ultimate strength of thin wall tee pipe for sodium cooled fast reactor under seismic loading

Pressure stresses generated due to supersonic steam jet induced hydrodynamic instabilities

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