توزیع بهینه اتصالات دارای میراگر جهت بهبود عملکرد لرزه ای قاب‌های صلب فولادی

نوع مقاله : مقاله پژوهشی

نویسندگان

دانشکده مهندسی عمران، دانشگاه تهران، تهران، ایران

چکیده

برای کاهش پاسخ سازه در برابر زلزله، قطعات با قابلیت اتلاف انرژی می‌توانند بر روی اتصالات فولادی جاگذاری گردند که این اتصالات با یک فنر دورانی برای تامین سختی و میرایی در سازه مدل‌سازی می­شوند. در این پژوهش با انجام تحلیل لرزه‌ای و عملیات بهینه‌سازی تحت چند رکورد زلزله سعی بر برآورد تخمینی برای بهترین محل قرارگیری اتصالات مذکور در سازه می‌باشد. در گذشته مطالعاتی بر روی این اتصالات در مقیاس سازه انجام شده است، به طوریکه در تمامی اتصالات سازه دو فنر مزبور قرار گرفته اند، اما این مقاله ترکیبی از این نوع اتصالات و اتصالات صلب در دو سازه 9 و 20 طبقه از سازه‌های مرجع SAC را بررسی می کند. در نهایت، عملکرد سازه با ترکیب اتصالات مجهز به میراگر و اتصالات صلب و همینطور سازه‌ با توزیع یکنواخت اتصالات  مجهز به میراگر مقایسه و بررسی گردید و مشاهده شد که عملکرد سازه با اتصالات ترکیبی با وجود مجهز بودن تعداد کمتری از این اتصالات به میراگر، بسیار بهتر از سازه با توزیع یکنواخت این نوع اتصالات می‌باشد. از سوی دیگر، رفتار خطی و غیرخطی سازه و اتصالات، مدل‌سازی شده و تحت بررسی قرار گرفت. همچنین در حالت بهینه به طور متوسط تحت سه زلزله، در سازه 9 و 20 طبقه به ترتیب 62 و 68% از اتصالات در حالت خطی و 58 و 61% در حالت غیرخطی، مجهز به میراگر شدند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Optimal distribution of connections with dampers to improve the performance of steel moment frames

نویسندگان [English]

  • Amir Mohammad Rabbani
  • Seyed Mehdi Zahrai
University of Tehran
چکیده [English]

To reduce the seismic response of steel frames, energy dissipating devices can be placed at connections. These connections can be modeled as a rotational spring and damper in parallel. In this paper, an attempt is made to estimate the best distribution of the connections, by time-history analysis and optimization operation. Although in the previous studies, these connections were distributed uniformly, in this research the combination of these connections in moment frames is proposed. Two 9 and 20-story frames with sections and dimensions based on SAC benchmark structures are studied. The seismic performance of optimized structures with connections equipped with dampers and rigid connections is evaluated and compared to that of the moment frame with the uniform placement of such connections. It is observed that the performance of hybrid structures, despite having fewer dampers in connections, is much better than the structure with uniform distribution of this type of connection. On the other hand, linear and nonlinear behavior of elements and connections in structure is developed. Also, in optimal conditions, 62 and 68% of the connections in linear and 58 and 61% in nonlinear behavior have been equipped with dampers respectively for 9 and 20-story structures.

کلیدواژه‌ها [English]

  • Semi-rigid connections
  • rigid connections
  • viscoelastic dampers
  • optimum distribution
  • particle swarm algorithm
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