Abstract




 
   

IJE TRANSACTIONS A: Basics Vol. 29, No. 1 (January 2016) 23-30    Article in Press

downloaded Downloaded: 439   viewed Viewed: 2470

  SEISMIC DESIGN OF STEEL STRUCTURES BASED ON DUCTILITY AND INCREMENTAL NONLINEAR DYNAMIC ANALYSIS
 
H. Kermani, F. Behnamfar and V. Morsali
 
( Received: July 30, 2015 – Accepted: December 24, 2015 )
 
 

Abstract    In this paper a simple tool for seismic design of steel structures for a selected ductility level is presented. For this purpose, a consistent set of earthquakes is selected and sorted based on the maximum acceleration of ground surface. The selected records are applied as the base motion to a single-degree-of-freedom system with strain hardening and the maximum response acceleration is determined for three levels of ductility. The response results of the incremental nonlinear dynamic analysis are presented in the shape of the maximum acceleration of the system versus the peak ground acceleration for a certain ductility demand. Using these graphs, the maximum acceleration and base shear of the system are calculated accounting for its nonlinear behavior, hence eliminating the need for the response modification factor. This is the main advantage of the presented diagrams for nonlinear seismic design of steel moment frames.

 

Keywords    ductility, incremental dynamic analysis, seismic design.

 

چکیده    در این مقاله، ابزاری ساده برای طراحی لرزهای سازههای فولادی به ازای سطوح شکلپذیری انتخاب شده ارائه شده است. برای این منظور، مجموعهای از زلزلههای سازگار انتخاب و براساس ماکزیمم شتاب دستهبندی شدهاند. رکوردهای انتخاب شده بهعنوان حرکت پی به سیستم یکدرجه آزاد با رفتار کرنش سخت شونده اعمال شده و حداکثر شتاب براساس سطوح شکلپذیری تعیین میگردد. نتایج پاسخهای حاصل از تحلیل فزاینده غیرخطی، بهصورت دیاگرامهایی مربوط به حداکثر بازتاب شتاب سیستم در مقابل ماکزیمم شتاب زمین (PGA) برای یک نیاز شکلپذیری خاص نشان داده شده است. با استفاده از این شکلها، بیشترین شتاب و برش پایه سیستم برای رفتار غیرخطی بدون نیاز به عامل ضریب رفتار محاسبه میگردد، که از مزایای اصلی این دیاگرامها برای طراحی لرزهای غیرخطی قابهای خمشی فولادی است.

References   

 

1.        Standard 2800,. Iranian Code of Practice for Seismic Resistant Design of Buildings, Standard No. 2800 (4th edition),. Building and Housing Research Center, (2015).

2.     Uniform Building Code (UBC),. International Conference of Building Officials, Whittier, California (1997)

3.     International Building Code (IBC),. International Code Council, Inc., USA. (2010)

4.     Structural Design Actions, Part 5: Earthquake Actions , NZS1170.5.  New Zealand Standards, (2004).

5.     Priestley, M., Calvi, G. and Kowalsky, M., "Direct displacement-based seismic design of structures", in 2007 NZSEE Conference, (2007).

6.     Grigorian, M. and Grigorian, C., "Performance control for seismic design of moment frames", Journal of Constructional Steel Research,  Vol. 67, No. 7, (2011), 1106-1114.

7.     Zhai, C.-H., Wen, W.-P., Zhu, T.-T., Li, S. and Xie, L.-L., "Inelastic displacement ratios for design of structures with constant damage performance", Engineering Structures,  Vol. 52, No., (2013), 53-63.

8.     American Society of Civil Engineers (ASCE),. Seismic Rehabilitation of Existing Buildings, ASCE41-13, Reston, Virginia (2013)

9.     Building & Housing Research Center (BHRC). URL: http://www.bhrc.gov.ir/.

10.   Kramer, S.L., "Geotechnical earthquake engineering, Prentice Hall Upper Saddle River, NJ,  Vol. 80,  (1996).

11.   NONLIN: Nonlinear dynamic time history analysis, url:Http://nees.Org/resources/nonlin.

12.   American society of civil engineers (ASCE),. Minimum design loads for buildings and other structures, asce7-2010, reston, virginia. (2010)

13.   Iranian seismic design code for oil industries, 2nd edition,. The oil ministry of iran. (2010)

14.   Newmark, N.M. and Hall, W.J., "Earthquake spectra and design", Earth System Dynamics, Vol. 1, No., (1982).

15.   Miranda, E., "Strength reduction factors in performance-based design", in Proceedings of EERC-CUREe Symposium, Berkeley, CA. Issue, (1997).





International Journal of Engineering
E-mail: office@ije.ir
Web Site: http://www.ije.ir