DOI QR코드

DOI QR Code

Evaluation of Ductility Factors for MDOF Systems in Special Steel Moment Resisting Frames

철골 연성 모멘트 골조에 대한 다자유도 시스템의 연성계수 평가

  • Published : 2004.12.01

Abstract

Ductiluty factor has played an important role in seismic design as it is key component of response modification factor(R). In this stuty, ductility factors() are calculated by multiplying ductility factor for SDOF systems() and MDOF modification factors(). Ductility factors() for SDOF systems are computed from nonlinear dynamic analysis undergoing different level of displacement ductiluty demands and period when subjected to a large number of recorded earthquake ground motions. The MDOF modification factors() are proposed to account for the MDOF systems, based on previous studies. A total of 108 prototype steel frames are designed to investigate the ductility factors considering the number of stories(4, 8 and 16-stories), framing system(Perimeter Frames, PF and Distributed Frames, DF), failure mechanism(Strong-Column Weak-Beam, SCWB and Weak-Column Strong-Beam, WCSB), soil profiles(SA, SC and SE in UBC 1997) and seismic zone factors(Z=0.075, 0.2 and 0.4 in UBC 1997). It is shown that the number of stories, failure mechanisms (SCWB, WCSB), and soil profiles have great influence on the ductility factors, however, the structural system(Perimeter frames, Distributed frames), and seismic zones have no influence on the ductility factors.

Keywords

special steel moment resisting frames;ductility factor;response modification factor;MDOF modification factor

References

  1. ATC, 'Structural Response Modification Factors,' ATC Report 19, Redwood City, 1995, 64pp
  2. ATC, 'A Critical Review of Current Approaches to Earthquake-Resistant Design,' ATC Report 34 Redwood City, 1995. 94pp
  3. Miranda, E., 'Evaluation of Site-Dependent Strength Reduction Factors,' Journal of Structural Engineering, ASCE, Vol.119. No.12, 1993, pp. 3503-3519 https://doi.org/10.1061/(ASCE)0733-9445(1993)119:12(3503)
  4. Miranda, E and Bertero, V.V., 'Evaluation of Strength Reduction Factors for Earthquake Resistant Design, 'Earthquake Spectra, Earthquake Engineering Research Institute, Vol.10, No.2, 1994, pp. 357-379 https://doi.org/10.1193/1.1585778
  5. Kang, C. K., 'Evaluation of Response Modifica-tion Factors for Special Steel Moment-Resisting Frames,' Ph. D. Dissertation, Kyonggi University, Seoul, Korea, 2003
  6. Hachem, M. M., BISPEC Version 1.1.2, University of California, Berkeley, 2000
  7. Nassar, A. A. and Krawinkler, 'H. Seismic Demands for SDOF and MDOF Systems,' John A. Blume Earthquake Engineering Center, Report No. 95, Stanford University, California, 1991, 204pp
  8. Miranda, E., 'Strength Reduction Factors in Performance-based Design,' Proc. EERC-CUREe Symposium in Honor of V. V. Bertero, Report No. UCB/EERC- 97/05, University of California, Berkeley, California. 1997, pp. 125-132
  9. ICBO, Uniform Building Code, International Con-ference of Building Officials, Whittier California, 1997
  10. AISC, Load & Resistance Factor Design, American Institute of Steel Construction, Inc, 2nd Edition, 1994
  11. FEMA 302, NEHRP Recommended Provisions for Seismic Regulations for New Buildings and Other Structures, Building Seismic Safety Council, Washington, D. C., 1997
  12. Tasi, K. C. and Li, J. W., 'DRAIN2D+ - A General Purpose Computer Program for Static and Dynamic Analysis of Inelastic 20 Structures Supplemented with a Graphic Processor,' Report No. CEER/R83-03, National Taiwan University, 1994
  13. FEMA 274, NEHRP Commentary on the Guidelines for The Seismic Rehabilitation of Building, Building Seismic Safety Council, Washington, D. C. 1997