DOI QR코드

DOI QR Code

Connection Performance of Steel Moment Frame with Out-of-Plane Beam Skew

면외방향 어긋난 보를 갖는 철골모멘트골조의 접합부 성능

  • Received : 2022.03.21
  • Accepted : 2022.04.19
  • Published : 2022.04.30

Abstract

This study investigated the behavior of out-of-plane skewed moment connections that were designed as IMFs, as per the Korean standards. A total of 14 finite element models were constructed with the consideration of two types (single- and double-sided connections) and four levels of skew angle (0°, 10°, 20°, and 30°). The results indicated that the skewed connections considered in this study met the acceptance criteria for IMFs given by the codes. However, the load-carrying capacities of skewed connections were decreased as the skew angle increased. For the connection with a skew angle of 30°, the peak load was noted to be 13% less and the energy dissipation capacity could be 26% less than that of non-skewed connection. In addition, because of the skewed nature, the stress distribution in the skewed beam flange near the connection was asymmetric and the stresses were concentrated on the beam inner flange. Column twisting induced by the skewed configuration was very small and negligible in the beam and column combination considered in this study.

본 연구에서는 국내 내진설계기준에 의해 중간모멘트골조로 설계된 철골 모멘트접합부에서 면외방향 어긋남을 갖는 보가 접합부의 거동에 미치는 영향을 평가하였다. 기둥을 중심으로 보가 접합되는 형식에 따라 2가지 경우(단면접합 및 양면접합)와 각각의 경우에 대하여 4개 수준의 어긋남 각도(0°, 10°, 20°, 30°)를 조합하여 총 14개의 유한요소해석 모델을 구성하였다. 해석결과, 면외 어긋남을 갖는 대상 모멘트접합부는 국내 구조기준에 따른 중간모멘트골조의 성능수준을 만족하는 것으로 나타났다. 그러나, 면외 어긋남 각도가 커질수록 접합부 시스템의 하중저항능력이 감소하였다. 면외 어긋남 각도가 30°인 접합부에서 보-기둥이 직교된 접합부에 비하여 최대 하중은 약 13% 감소하였고, 층간 변위각 0.02 rad까지의 에너지 소산능력은 최대 26% 감소하였다. 또한, 어긋남 형상에 기인하여 접합부와 인접한 보 플랜지에서 응력이 비대칭으로 분포되며, 보 플랜지와 기둥 플랜지가 예각을 이루는 내측 플랜지(Inner Flange)에 응력이 집중되었다. 본 연구에서 고려한 보-기둥 접합에서는 어긋난 보에 의해 기둥의 축방향 회전에 미치는 영향은 미미하여 무시할 만 하였다.

Keywords

Acknowledgement

본 연구는 순천대학교 교연비 사업에 의하여 연구되었습니다.

References

  1. MOLIT. (2019), KDS 41 17 00: Seismic Design Code for Building Structures, Ministry of Land, Infrastructure and Transport, Korea.
  2. AISC. (2016a), ANSI/AISC 341-16: Seismic Provisions for Structural Steel Buildings, American Institute of Steel Construction, Chicago, IL.
  3. Hamberger, R. O., Krawinkler, H., Malley, J. O., and Adan, S. M. (2009), NEHRP Seismic Design Technical Brief No. 2, Seismic Design of Steel Special Moment Frames: A Guide for Practicing Engineers, National Institute of Standards and Technology, Gaithersburg, MD.
  4. Kim, D. W., Sim, H. B., and Uang, C. M. (2010), Cyclic Testing of Non-orthogonal Steel Moment Connections for LAX TBIT Modification, Report No. TR-09/04, University of California, San Diego, La Jolla, CA.
  5. Kim, D. W, Hall, S. C., Sim, H. B. and Uang, C. M. (2016), Evaluation of Sloped RBS Moment Connections, Journal of Structural Engineering, ASCE, 142(6), 1-10.
  6. Mashayekh, A. (2017), Sloped Connections and Connections with Fillet Welded Continuity Plates for Seismic Design of Special Moment Frames, Ph.D. dissertation, La Jolla, CA: University of California, San Diego, Department of Structural Engineering.
  7. Hong, J. K. (2019), Sloped RBS Moment Connections at Roof Floor Subjected to Cyclic Loading: Analytical Investigation, International Journal of Steel Structures, KSSC, 19(1), 329-339. https://doi.org/10.1007/s13296-018-0198-4
  8. Prinz. G, S. and Richards, P. W.. (2016), Demands on Reduced Beam Section Connections with Out-of-Plane Skew, Journal of Structural Engineering, ASCE, 142(1), 04015095-1-04015095-9. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001360
  9. Asl, M. H., Saeidzadeh, M., and Momenzadeh, S. (2019), Evaluation of Friction Loss in End-Plate Moment Connections with Skewed Beam, International Journal of Steel Structures, KSSC, 19(6), 1767-1784. https://doi.org/10.1007/s13296-019-00246-y
  10. MOLIT. (2016), 2016 Korean Building Code, Ministry of Land, Infrastructure and Transport, Korea.
  11. MOLIT. (2019), KDS 41 31 00: Structural Design Code for Steel Buildings, Ministry of Land, Infrastructure and Transport, Korea.
  12. ABAQUS (2021), ABAQUS/CAE users' guide, Ver. 6.24, Johnston, RI: Dassault Systems Simulia.
  13. Kauffmann, E. J., Metrovich, B. R., and Pense, A. W. (2001), Characterization of Cyclic Inelastic Strain Behavior on Properties of A572 Gr.50 and A913 Gr.50 Rolled Sections, ATLASS Report No. 01-13, National Center for Engineering Research on Advanced Technology for Large Structural Systems, Lehigh University, Bethlehem, PA.
  14. Hartioper, A. R., Castro e Sousa, A., and Lignos, D. G. (2021), Constitutive Modeling of Structural Steels: Nonlinear Isotropic/Kinematic Hardening Material Model and Its Calibration, Journal of Structural Engineering, ASCE, 147(4), 04021031-1-04021031-17. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002964
  15. Hong, J. K., Park, Y. C., and Sim, H. B. (2019), Cyclic Performance of Easy Quality (EQ) Moment Connections as an Intermediate Steel Moment Frame, International Journal of Steel Structures, KSSC, 19(4), 1272-1282. https://doi.org/10.1007/s13296-019-00207-5
  16. MOLIT. (2017), KDS 14 31 60: Seismic Design Code for Steel Structures, Ministry of Land, Infrastructure and Transport, Korea.
  17. El Tawil, S., Mikesell, T., Vidarsson, E., Kunnath, S. K. (1998), Strength and Ductility of FR Welded-Bolted Connections, SAC Joint Venture, Report No. SAC/BD-98/01, Sacramento, CA.