Journal of the Korea institute for structural maintenance and inspection (한국구조물진단유지관리공학회 논문집)

Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회)
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Evaluation of Shear Deformation Energy and Fatigue Performance of Single-layer and Multi-layer Metal Bellows

단층 및 다층 금속 벨로우즈의 전단 변형 에너지 및 피로성능 평가

  • 이경석 (부산대학교 지진방재연구센터) ;
  • 유진석 (태성후렉시블 기술연구소) ;
  • 정영수 (부산대학교 지진방재연구센터)
  • Received : 2023.12.04
  • Accepted : 2023.12.28
  • Published : 2024.02.28
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Abstract

Seismic safety of expansion joints for piping systems has been underscored by water pipe ruptures and leaks resulting from the Gyeongju and Pohang earthquakes. Metal bellows in piping systems are applied to prevent damage from earthquakes and road subsidence in soft ground. Designed with a series of corrugated segments called convolutions, metal bellows exhibit flexibility to accommodate displacements. Several studies have examined variations in convolution shapes and layers based on the intended performance to be evaluated. Nonetheless, the research on the seismic performance of complex bellows having multiple corrugation heights is limited. In this study, monotonic loading tests, cyclic loading tests, and fatigue tests were conducted to evaluate the shear performance in seismic conditions, of metal bellows with variable convolution heights. Single- and triple-layer bellows were considered for the experimentation. The results reveal that triple-layer bellows exhibit larger maximum deformation and fatigue life than single-layer bellows. However, the high stiffness of triple-layer bellows in resisting internal pressure poses certain disadvantages. The convolutions are less flexible at lower displacements and experience leakage at a rate related to the variable height of the convolutions in certain conditions. At lower deformation rates, the fatigue life is rated higher as the number of layers increase. It converges to a similar fatigue life at higher deformation rates.

경주 및 포항지진으로 인한 지하매설배관의 파열 및 누수가 발생하여 내진 안전성 확보의 중요성이 증대되고 있다. 배관시스템의 내진 확보를 위해 금속 벨로우즈 신축관이음이 적용되고 있다. 금속 벨로우즈는 일련의 주름 형상으로 제작되어 비교적 낮은 강성으로 유연하게 변형으로부터 대응한다. 금속 벨로우즈의 목적에 따라 다양한 주름 형상과 겹 수로 제작되고 이와 관련한 다양한 연구가 수행되었다. 하지만 산높이가 복합적인 벨로우즈의 전단 거동에 대한 내진성능을 평가한 연구는 미비하다. 따라서 본 연구는 복합적인 산 높이로 구현된 벨로우즈의 전단 내진성능을 분석하기 위한 단조하중실험, 점증반복하중실험 및 피로반복실험을 수행하였다. 실험은 한 겹 및 세 겹으로 제작된 벨로우즈를 대상으로 수행하였으며, 한 겹 보다 세 겹으로 제작된 벨로우즈의 최대 변형 및 피로 수명이 높은 것으로 평가되었다. 하지만 세 겹의 벨로우즈는 내압에 비해 높은 강성으로 주름산의 변형이 더 낮은 변위에서 발생하며, 복합적인 주름산의 높이와 관련하여 특정 조건에서는 누수가 빠르게 발생하였다. 피로 수명은 낮은 변형률에서 많은 겹 수의 벨로우즈가 높게 평가되었고, 높은 변형률에서는 동일한 피로 수명으로 수렴하였다.

Keywords

Acknowledgement

본 연구는 국토교통부/국토교통과학기술진흥원의 지원으로 수행되었으며, 이에 감사드립니다(과제번호: RS-2022-00143468).

References

  1. Ministry of the Interior and Safety (2018), 2017 Pohang Earthquake White Paper, Central Disaster and Safety Countermeasures Headquarters, Sejong, Korea (in Korean).
  2. KDS 57 (2022), Design Criteria for Water Supply, Ministry of Environment, Sejong, Korea (in Korean).
  3. Ministry of the Interior and Safety (2016), Seismic Design Criteria of Fire Fighting Facilities, Ministry of the Interior and Safety, Sejong, Korea (in Korean).
  4. Lv, Y., Liang, L. R., Li, Y. W., Chen, Y., and Chouw, N. (2021), Experimental and Finite-Element Study of Buried Pipes Connected by Bellow Joint under Axial Cyclic Loading, Journal of Pipeline Systems Engineering and Prectice, 12(1), 04020069.
  5. Lv, Y., Liu, C. F., Huang, X., Chen, Y., and Chouw, N. (2021), Experimental and Finite-Element Studies of Buried Pipes Connected by a Bellow Joint under Cyclic Shear Loading, Journal of Pipeline Systems Engineering and Prectice, 12(4), 04021057.
  6. Xiang, X. M., Lu, G., Li, Z. X., and Lv, Y. (2017), Finite Element Analysis and Experimental Study on a Bellows Joint, Engineering Structures, 151(15), 584-598. https://doi.org/10.1016/j.engstruct.2017.08.034
  7. Golovina, N. Y. (2019), Optimization of Design Parameters of Bellows Expansion Joints, International Journal of Mechanical and Production Engineering Research and Development, 9(3), 1413-1420. https://doi.org/10.24247/ijmperdjun2019148
  8. Kim, S. W., Chang, S. J., Park, D. U., and Jeon, B. G. (2023a), Seismic Performance Evaluation on Bending Deformation of 2-Ply and 3-Ply Bellows Expansion Pipe joints, Journal of the Korea Institute for Structural Maintenance and Inspection, 27(2), 33-41 (in Korean, with English abstract).
  9. Kim, S. W., Chang, S. J., Jeon, B. G., and Ju, B. S. (2023b), Limit state assessment for bending deformation of multi-ply bellows systems, Journal of Constructional Steel Research, 206, 107928.
  10. Liu, J., Li H., Lv Y., Li, L., and Sun, C. (2018), "Size Effect" Related Hydroforming Characteristics of Thin-Walled 316-L Bellow considering Pressure Change, The International Journal of Advanced Manufacturing Technology, 95, 505-522. https://doi.org/10.1007/s00170-017-1208-y
  11. Vinoth, A., Vignesh, B., Khurana, L., and Rai, A. (2016), A Review on Application of Bellows Expansion Joints and Effect of Design Parameters on System Characteristics, Indian Journal of Science and Technology, 9(32), 1-8. https://doi.org/10.17485/ijst/2016/v9i32/94320
  12. Seo, Y. D., Lee, K. S., Yu, J. S., and Jeong, Y. S. (2023), Ultimate Bending Performance and Fatigue Life of Single-layer and Multi-layer Bellows, Journal of Korean Society for Advanced Composite Structures, 14(1), 9-16 (in Korean, with English abstract). https://doi.org/10.11004/kosacs.2023.14.1.009
  13. Kim, J. D. (2016), Design and Performance Evaluation of Forming Bellows for LNG Carriers, National Korea Maritime and Ocean University, Doctor of Engineering thesis (in Korean, with English abstract).
  14. Hao, Z., Luo, J., Jin, Y., Wei, W., and Lei, L. (2020), Failure analysis of corrugated metal hose under ultimate repeated bending process, Engineering Failure Analysis, 109, 104295.
  15. Hao, Z., Chen, Y., Chen, L., Cai, Y., and Luo, J. (2022), Ultimate bending performance and fatigue life of U-shaped metal bellows, Journal of Mechanical Engineering Science, 236(16), 9186-9199. https://doi.org/10.1177/09544062221092928
  16. Krawinkler, H. (1992), Guidelines for Cyclic Seismic Testing of Components of Steel Structures, Applied Technology Council, Redwood City, CA, 14.
  17. Nassar, A. A. (1991), Seismic demands for SDOF and MDOF systems. Stanford University.
  18. ISO 16670 (2003), Timber Structures - Joints Made with Mechanical Fasteners - Quasi-Static Reversed - Cyclic Test Method, International Standards Organization, Switzerland.