طراحی پلاستیک قاب خمشی فولادی بر مبنای عملکرد و مقایسه آن با روش مبتنی بر نیرو

نوع مقاله : مقاله پژوهشی

نویسندگان

1 گروه مهندسی عمران، دانشکده مهندسی، دانشگاه کاشان

2 گروه مهندسی عمران، دانشکده مهندسی، دانشگاه کاشان، شهر کاشان، ایران

چکیده

در روش­های متداول طراحی لرزه­ای، که نیروی اعضا به حد مقاومت محدود می­گردند، عملکرد سازه به طور مستقیم در طراحی وارد نمی­شود. تنها موردی که در روش نیرو به عنوان کنترل عملکرد سازه لحاظ می­گردد، کنترل جابجایی نسبی سازه در گام نهایی طراحی است. این ضعف روش طراحی مبتنی بر نیرو، سبب شده که توجه ویژه­ای به روش­های طراحی مبتنی بر عملکرد معطوف گردد. روش طراحی پلاستیک بر اساس عملکرد یکی از روش­های طراحی عملکردی است که در آن سطح خرابی و مکانیزم خرابی مطلوب در گام­های نخستین طراحی از پیش مشخص است. انتظار می­رود که سازه طراحی شده با روش مذکور از لحاظ رفتاری انطباق بیشتری با مکانیزم مطلوب داشته باشد. در این تحقیق هر دو روش طراحی برای سازه­های چهار، هشت، دوازده و شانزده طبقه به کار گرفته شده و رفتار غیرخطی سازه­ها با تحلیل­های غیرخطی استاتیکی و دینامیکی بررسی شده‌است. تحلیل­های انجام شده نشان می­دهد سازه­های طراحی شده با روش پلاستیک بر اساس عملکرد دارای مکانیزم خرابی نزدیک­تری به آنچه در روند طراحی فرض شده‌است، می­باشند. همچنین سازه­های مذکور در تحلیل استاتیکی غیرخطی، شکل ­پذیری بیشتری از خود نشان داده اند. در این سازه­ها، توزیع مفاصل پلاستیک در تحلیل دینامیکی غیرخطی به صورت یکنواخت و فراگیر است. همچنین تمرکز خرابی شدید و مکانیزم موضعی در ستون­های سازه های طراحی شده با روش طراحی پلاستیک براساس عملکرد به دلیل مقاومت بیشتر آن­ها ایجاد نمی ­شود.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Performance Based Plastic Design of Steel Moment Frame and Comparing It with Force Based Design

نویسندگان [English]

  • Fatemeh Mousavinejad 1
  • Hassan Ostad-Hossein 2
1 Civil engineering department, faculty of engineering, University of Kashan
2 Civil engineering department, Faculty of engineering, University of Kashan, Kashan, Iran.
چکیده [English]

In conventional seismic design methods the performance of structure has not been considered in base shear estimation and structural drift, as a measure of damage, will be checked at the end of design stages. This weakness of force-based design (FBD) methods causes special attention to performance-based design. Performance-based plastic design (PBPD) is of performance-based design (PBD) in which the desired damage level and plastic mechanism of the structure are predefined at the beginning of the design procedure, to estimate internal forces. It is expected that applying PBPD ends to a structural behavior with more compliance with the desired mechanism. In this paper, the priority of PBPD over FBD has been investigated. The PBPD and FBD methods are applied to the design of four special steel moment frames of 4, 8, 12, and 16 stories. The nonlinear behavior of designed structures has been evaluated by push-over and nonlinear time history analysis. Analysis results show that the PBPD frame has mechanism mode closer to assumed mechanism mode in the design procedure. Another conclusion is that the PBPD frame mechanism in the push-over analysis is more ductile than the FBD frame. Also, it concluded that in the PBPD frame, plastic hinges are approximately distributed uniformly all over the structure. The general reason for PBPD ductility improvement, versus FBD, is the strength of columns which prevent undesirable mechanism.

کلیدواژه‌ها [English]

  • Performance based plastic design
  • force based design
  • Push over Analysis
  • time history analysis
  • performance objectives
[1]    M. Safari Gorji, J.J. Roger Cheng, Plastic analysis and performance-based design of coupled steel plate shear, Engineering Structures, 166 (2018) 472-484.
[2]    S. Sattar, Evaluating the consistency between prescriptive and performance-based seismic design approaches for reinforced concrete moment frame buildings, Engineering Structures, 174 (2018) 919-931.
[3]    R. Allahvirdizadeh, M. Khanmohammadi, M.S. Marefat, Probabilistic comparative investigation on introduced performance-based seismic design and assessment criteria, Engineering Structures, 151 (2017) 206-220.
[4]    FEMA-445, Next-Generation Performance-Based Seismic Design Guidelines, 2006.
[5]    J. Bai, J. Ou, Earthquake-resistant design of buckling-restrained braced RC moment frames using performance-based plastic design method, Engineering Structures, 107 (2016) 66-79.
[6]    Y.J. Cha, J.W. Bai, Seismic fragility estimates of a moment-resisting frame building controlled by MR dampers using performance-based design. Engineering Structures, 116 (2016) 192-202.
[7]    M.Ch. Basim, H.E. Estekanchi, Application of endurance time method in performance-based optimum design of structures, Structural Safety, 56 (2015) 52-67.
[8]    FEMA-356, Prestandard and Commentary for the Seismic Rehabilitation of Buildings, Federal Emergency Management Agency, Washington, D.C., 2000.
[9]    ATC 40,  Seismic evaluation and retrofit of existing concrete buildings, Redwood City (CA): Applied Technology Council, 1996.
[10] P. Fajfar, A nonlinear analysis method for performance-based seismic design, Earthquake Spectra, 16(3) (2000) 573-92.
[11] Q. Xue, Adirect desplacement-based seismic design prcure of inelastic structures, Engineering Structures,23(1) (2001) 1453-60.
[12] S.H. Chao, S.C. Goel, Performance-Based Seismic Plastic Design of Seismic resistant Spetial Truss Moment Frames (STMF), Report No. UMCCE 06-03, 2006a.
[13] S.C. Goel, S.S. Lee, S.H. Chao, Performance-based seismic design of steel moment frames using target drift and yield mechanism, 13th World Conference on Earthquake Engineering, 2004.
[14] S.C. Goel, S. Chao, S. LeelataviWat, S. Lee, Performance-Based Plastic Design (PBPD) Method for Earthquake-Resistant Structures, 2008.
[15] S. Shoeibi, M. Kafi, M. Gholhaki, New performance-based seismic design method for structures whit structural fuse system, Engineering Structures, 132 (2017) 745-760.
[16] Structural and earthquake engineering software, ETABS, CSi Analysis Refrence Manual, 2015.
[17] AISC 360, Specifi cation for Structural Steel Buildings, ANSI/AISC 360-10, American Institute of Steel Con- struction, Chicago, IL, 2010.
[18] ASCE 7, Minimum Design Loads for Buildings and Other Structures (ASCE 7-10), American Society of Civil Engineers, Reston, Virginia, 2010.
[19] A. Ghorbarah, Performance-based design in earthquake engineering: state of development, Engineering Structure, 23(8) (2001) 878-884.
[20] G.W. Housner, The Plastic Failure of Frames during Earthquakes, Proceedings of the Second World Conference on Earthquake Engineering:  997-1012. Tokyo: International Association of Earthquake Engineering,  (1960) 997-1012.
[21] S.H. Chao, S. C. Goel, Performance-Based Seismic Design of EBF Using Target Drift and Yeild Mechanism as Performance Criteria, Report No. UMCCE OS-OS. Ann Arbor, MI.:Department of Civil and Environmental Engineering, Univercity of Michigan, 2007.
[22] S. Leelataviwat, S.C. Goel, B. Stojadinovic, Toward Performance-Based Seismic Design of Structures, Earthquake Spectra, 15(3) (1999) 435-461.
[23] S.H. Chao, S.C. Goel, S.S. Lee, A Seismic Design Latral Force Distribution Based on Inelastic State of Structures, Earthquake Spectra, 23(3) (2007) 547-569.
[24] N.M. Newmark, W.J. Hall, Earthquake Spectra and Design. EI Cerrito, CA: Earthquake Engineering Research Institute, 1982.
[25] UBC, Structural Engineering Design provisions, Uniform Building Code, Vol. 2, International Conference of Building Officials, (1994).
[26] A. Gupta, H. Krawinkler, Seismic Demands for Performance Evaluation of Steel Moment Resisting Frame Structures, John A. Blume Earthquake Engineering Center Report No. 132, Department of Civil Engineering, Stanford University, (1999).
[27] D. Sahoo, S.H. Chao, Performance-Based Plastic Design Method for Buckling Restrained Braced Frames, Engineering Structures, 32(9) (2010) 2950–2958.