ارزیابی اثرات برش تیرها و ستون‌ها بر عملکرد لرزه‌ای سازههای بتن مسلح

نوع مقاله : علمی - پژوهشی

نویسندگان

1 گروه مهندسی عمران-دانشکده فنی و مهندسی-دانشگاه مازندران-بابلسر-ایران

2 استادیار دانشگاه مازندران، دانشکده فنی و مهندسی، مازندران، بابلسر، ایران

چکیده

نقش شکست برشی در رفتار لرزه‌ای سازه‌های بتن مسلح از اهمیت فراوانی برخوردار می‌باشد. معمولا، تحلیل غیرخطی تیرها و ستون‌ها در سازه‌های بتنی بر اساس رفتار خمشی اعضا بوده و اثرات برش در آنها نادیده گرفته می‌شود. در چنین تحلیل‌هایی تنها رفتار خمشی عضو در نظر گرفته شده است؛ درحالیکه نتایج آزمایشگاهی احتمال شکست اعضای بتن مسلح در حالت‌های قبل از رسیدن به ظرفیت خمشی نهایی را نشان می‌دهد. در این مطالعه، مدلی عددی شامل مفاصل‌ چرخشی، برای شبیه‌سازی اثرات ظرفیت برشی تیرها و ستون‌ها بر اساس مکانیزم شکست مواد پیشنهاد شده است. به منظور بررسی دقت مدل پیشنهادی در تیرها و ستون‌ها، نتایج به دست آمده از تحلیل غیرخطی با نتایج آزمایشگاهی مقایسه شد؛ به طوریکه نتایج پیش‌بینی شده توسط مدل پیشنهادی تطابق مناسبی با نتایج آزمایشگاهی دارد. علاوه بر این، مدل پیشنهادی در سطح سازه مورد ارزیابی عملکردی قرار گرفت و به همین منظور، قابی بتن مسلح در دو حالت مختلف 1- تحلیل با استفاده از مدل پیشنهادی با در نظر گرفتن اثرات برش و 2- تحلیل بر اساس مدل پیشنهادی با صرف نظر کردن از اثرات برش در اعضا بررسی شده است. نتایج حاصل، اهمیت در نظر گرفتن اثر برش در پیش‌بینی رفتار غیرخطی قاب‌ها توسط مدل پیشنهادی را نشان می‌دهد؛ که می‌تواند روشی جایگزین برای روش‌های متداول باشد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Assessment of shear effects of RC beams and columns on seismic performance of RC structures

نویسندگان [English]

  • meysam omidalizadeh 1
  • mehdi nematzadeh 2
  • Javad Shayanfar 1
1 Department of civil engineering, University of Mazandaran, Babolsar, Iran
2 Ph.D., Department of Civil Engineering, University of Mazandaran, Babolsar, Iran
چکیده [English]

Shear failure plays a significant role in the seismic behavior of reinforced concrete (RC) structures. Generally, nonlinear analysis of the beams and columns in concrete structures is based on the flexural behavior of the members, and shear effects are generally ignored. Although in such an analysis, only the flexural behavior of members is considered, experimental results reveal the likelihood of the failure of RC members before reaching the ultimate flexural capacity. In this paper, a numerical model including rotational springs was developed to simulate the effects of the shear capacity of beams and columns based on material failure mechanisms. In order to evaluate the accuracy of the proposed model for beams and columns, the results gained by the nonlinear analysis were compared with the experimental results, which revealed a good agreement of the results predicted by the proposed model with those of experiments. Furthermore, the proposed model was assessed at the structural level in terms of performance, and to do so, an RC frame was investigated in two different modes: a) analysis using the proposed model considering shear effects and b) analysis based on the proposed model ignoring shear effects in the members. The obtained results suggest the importance of taking the effect of shear into account in predicting the nonlinear behavior of frames by the proposed model which may present an alternative to common methods.

کلیدواژه‌ها [English]

  • Analytical model
  • Non-linear static (pushover) analysis
  • Shear effect
  • Shear failure
  • SAP2000 software
  • RC structures
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