0

Full Content is available to subscribers

Subscribe/Learn More  >

Assessment Method for Complex Cracked Pipe Using Equivalent Pipe Concept

[+] Author Affiliations
Kyung-Dong Bae, Ho-Wan Ryu, Seung-Jae Kim, Hyun-Suk Nam, Yun-Jae Kim

Korea University, Seoul, Korea

Paper No. PVP2016-63427, pp. V06AT06A007; 8 pages
doi:10.1115/PVP2016-63427
From:
  • ASME 2016 Pressure Vessels and Piping Conference
  • Volume 6A: Materials and Fabrication
  • Vancouver, British Columbia, Canada, July 17–21, 2016
  • Conference Sponsors: Pressure Vessels and Piping Division
  • ISBN: 978-0-7918-5042-8
  • Copyright © 2016 by ASME

abstract

This paper proposes the assessment method of complex cracked pipes. Complex crack is the form of crack existing through-wall crack and surface crack at the same time [1–2]. Complex crack is mainly caused by PWSCC phenomenon in pipe with overlay maintenance welding. At first, circumferential surface crack is developed by PWSCC phenomenon in the weakest point which is nickel alloy welding point. And this crack propagates to axisymmetric crack in inner surface. After that the crack initiates in not only pipe part but also overlay maintenance welding part, complex crack shape which is main subject in this paper is formed. Unlike through-wall cracked pipes or surface cracked pipes, complex cracked pipes have a complex behavior because of combining through-wall crack behaviors and surface crack behaviors in cracked part. So calculating J-integral and defining amount of crack growth of complex cracked pipes are more difficult than those of through-wall cracked pipes and surface cracked pipes. Therefore, in this paper, the concept using equivalent pipe is proposed for assessment method of complex cracked pipes. To determine equivalent pipe, maximum loads of various through-wall cracked pipes having same circumferential crack size and different thickness are calculated. The reason why through-wall cracked pipe is selected for equivalent pipe is that many researches about J-integral and crack growth of through-wall cracked pipes are already performed and those results are sufficiently validated. In addition, it can be not only directly utilized procedure of leak before break assessment but also compared previous research results using only through-wall cracked part in complex cracked pipes referred to reduced thickness method. Maximum loads of complex cracked pipes and through-wall cracked pipes are calculated using stress-modified fracture strain model in finite element analysis [3–6]. This model is technics removing load bearing capacity in elements which satisfy damage criteria. Damage criteria is determined by using tensile experiment results, fracture toughness experiment results and validated by comparing with real size pipe experiment results. All the experiment results are in pipe fracture encyclopedia published by Battelle [7]. The experiments utilized in the paper are performed in operating temperature 288°C and materials of pipes are stainless steel SA376 TP304 and carbon steel A106 Gr.B. Finally, the results of equivalent through-wall cracked pipe thickness are provided.

Copyright © 2016 by ASME
Topics: Pipes

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In