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Re-evaluation of Force Transfer Mechanism of Welded Steel Moment Connections

용접 철골 모멘트접합부의 응력전달 메커니즘 재평가

  • Published : 2005.04.01

Abstract

Employing the classical beam theory for the design of welded steel moment connections has been brought into question by several researchers since the 1994 Northridge earthquake. In this study, the load transfer mechanism in various welded steel moment connections is comprehensively reviewed mainly based on recent studies conducted by the writer. Available analytical and experimental results showed that the load path in almost all the welded steel moment connections is completely different from that as predicted by the classical beam theory. Vertical plates near the connection such as the beam web, the web of the straight haunch, and the rib act as a strut rather than following the classical beam theory. The shear force transfer in the RBS connection is essentially the same as that in PN type connection. Some simplified analytical models that can be used as the basis of a practical design procedure are also presented.

용접 철골 모멘트접합부는 일반적으로 평면유지의 가정을 전제한 초등휨이론에 의해 설계되어 왔다. 그러나 1994년 노스리지 지진 이후 보-기둥 접합부의 설계에 초등휨이론을 적용하는 것은 타당치 않음이 몇몇 연구자에 의해 제기된 바가 있다. 본 연구에서는 필자의 최근 해석 및 실험연구를 주 근거로 하여 다양한 형식의 접합부의 응력전달 메커니즘을 재평가하고, 거의 모든 용접 모멘트접합부의 설계에 초등휨이론을 적용하는 것이 부적절함을 보이고자 하였다. 보의 웨브, 수평헌치의 웨브, 리브 등과 같은 수직 플레이트 접합요소는 모두 스트럿 작용에 의해 응력을 전달하는 유사성이 있음을 해석적, 실험적으로 확인하였다. 또한 최근 가장 큰 주목을 받고 있는 고연성 RBS 접합부의 전단력 응력전달 메커니즘은 PN형식 접합부의 그것과 크게 다르지 않음을 확인하였다. 아울러 접합부 설계에 유용하게 활용될 수 있는 단순화된 해석적 응력전달 모형을 소개하였다.

Keywords

References

  1. SAC, 'Seismic design criteria for new moment-resisting steel frame construction,' Report No. FEMA 350, SAC Joint Venture, Sacramento, Calif, 2000
  2. Lee, C.-H. and Uang, C.-M. 'Analytical modeling of dual panel zone in haunch repaired steel MRFs,' Journal of Structural Engineering, ASCE, Vol. 123, No.1, 1997, pp. 20-29 https://doi.org/10.1061/(ASCE)0733-9445(1997)123:1(20)
  3. Popov, E. P., Yang, T.-S., and Balan, T., 'Steel MR Connection Design Critically Reviewed,' Proc. of EERC-CUREe Symposium in Honor of Vitelmo V. Bertero, 1997, pp. 65-74
  4. Goel, S. C., Stojadinovic, B, and Lee, K.-H, 'Truss Analogy for Steel Moment Connections,' Engineering Journal, 2nd Quarter, 1997, pp. 43-53
  5. Gere, J. M. and Timoshenko, S. P. Mechanics of Materials, Brooks/Cole Engineering Div., Calif, 1984
  6. Lee, C.-H. and Yoon, T.-H. 'Analytical re-examination of shear transfer in welded steel moment connection,' Proc. of 1st Japan-Korea Joint Seminar on Earthquake Engineering for Building Structures, Seoul, Korea, 1999, pp. 119-128
  7. Uang, C.-M. and Bondad, D, 'Static Cyclic Testing of Pre-Northridge and Haunch Repaired Steel Moment Connections,' SAC 96-01, Part 1, 1996, pp. 133-139
  8. Lee, C.-H. and Park, J.-W, 'Full-scale cyclic seismic testing of column-tree steel moment connections,' Journal of Korea Society of Steel Construction, Vol. 10, No. 4, 1998, pp. 629-639
  9. Miller, D. K., 'Lessons learned from the Northridge earthquake,' Engineering Structures, Vol. 20, Nos. 4-6, 1998, pp. 249-260 https://doi.org/10.1016/S0141-0296(97)00031-X
  10. Bruneau, M., Uang, C.-M. and Whittaker, A. Ductile Design of Steel Structures-Design of ductile moment-resisting frames, MaGraw-Hill, New York, NY., 1998, pp. 273-380
  11. Stojadinovic, B., Goel, S. C., Lee, K.-H., Margarian, A. G. and Choi, J.-H, 'Parametric tests on unreinforced steel moment connections,' Journal of Structural Engineering ASCE, Vol. 126, No. 1, 2000, pp. 40-49 https://doi.org/10.1061/(ASCE)0733-9445(2000)126:1(40)
  12. Uang, C.-M., Bondad, D. and Lee, C.-H., (1998). 'Cyclic Seismic Performance of Haunch Repaired Steel moment Connections: Experimental Testing and Analytical Modeling,' Engineering Structures, Vol. 20, Nos. 4-6, 1998, pp. 552-561 https://doi.org/10.1016/S0141-0296(97)00093-X
  13. Uang, C.-M., Yu, Q.-S., Noel, S. and Gross, J., 'Cyclic Testing of Steel moment Connections Rehabilitated with RBS or Welded Haunch,' Journal of Structural Engineering, ASCE, Vol. 126, No. 1, 2000, pp. 57-68 https://doi.org/10.1061/(ASCE)0733-9445(2000)126:1(57)
  14. Yu, Q.-S., Uang, C.-M. and Gross, J., 'Seismic Rehabilitation Design of Steel Moment Connection with Welded Haunch,' Journal of Structural Engineering, ASCE, Vol. 126, No. 1, 2000, pp. 69-78 https://doi.org/10.1061/(ASCE)0733-9445(2000)126:1(69)
  15. SAC, Technical Report: Experimental Investigations of Beam-Column Subassemblies, Report No. SAC-96-01, SAC Joint Venture, Sacramento, CA, 1996
  16. Lee, C.-H. and Uang, C.-M. 'Analytical modeling and seismic design of steel moment connections with welded straight haunch,' Journal of Structural Engineering, ASCE, Vol. 127, No. 9, 2001, pp. 1028-1035 https://doi.org/10.1061/(ASCE)0733-9445(2001)127:9(1028)
  17. Lee, C.-H., Jung, J.-H., Oh, M.-H. and Koo, E.-S., 'Cyclic seismic testing of steel moment connections reinforced with welded straight haunch,' Engineering Structures, Vol. 25, 2003, pp. 1743-1753 https://doi.org/10.1016/S0141-0296(03)00176-7
  18. Zekioglu, A., Mozaffarian, H., Chang, K. L. and Uang, C.-M. 'Designing After Northridge,' Modern Steel Construction, 37 (3), 1997, pp. 36-42
  19. Lee, C.-H., 'Seismic design of rib-reinforced steel moment connections based on equivalent strut model,' Journal of Structural Engineering, ASCE, Vol. 128, No. 9, 2002, pp. 1121-1129 https://doi.org/10.1061/(ASCE)0733-9445(2002)128:9(1121)
  20. Lee, C.-H., Jung, J.-H., Oh, M.-H. and Koo, E.-S., 'Experimental study of cyclic seismic behavior of steel moment connections reinforced with ribs,' Journal of Structural Engineering, ASCE, Vol. 131, No. 1, 2005, pp. 108-118 https://doi.org/10.1061/(ASCE)0733-9445(2005)131:1(108)
  21. Lee, C.-H., Jeon, S.-W., Kim, J.-H., Kim, J.-H. and Uang, C.-M., 'Seismic performance of reduced beam section steel moment connections: effects of panel zone strength and beam web connection method,' 13th World Conference on Earthquake Engineering, Vancouver, B.C., Canada, August 1-6, 2004, Paper No. 3449