بررسي عملكرد لرزه‌يي اتصال تير I به ستون قوطي شكل با ورق هاي فوقاني و تحتاني به روش اجزا تشكيل دهنده

Seismic Evaluation of I-Shaped Beam to Box-Column Connections with Top and Seat Plates by the Component Method

طي سال‌هاي گذشته، براي تعيين رفتار و طراحي شكل‌پذيري قاب‌هاي خمشي مقاوم در برابر بار لرزه‌يي، پژوهش‌هاي بسياري شامل: انجام عمليات آزمايشگاهي و همچنين ارايه‌ي مدل‌هاي تحليلي و مكانيكي براي تعيين مقاومت و پايداري اتصالات خمشي در قاب‌هاي مقاوم لرزه‌يي صورت گرفته است. در اين نوشتار با استفاده از روش «مدل اجزا تشكيل‌دهنده» به رفتار اتصال تير I به ستون قوطي‌شكل با ورق‌هاي فوقاني و تحتاني پرداخته شده است. همچنين جهت بررسي جامع رفتار اتصال در محدوده‌ي وسيعي از رفتار غيرخطي از روابط مدل زوال اصلاح‌شده‌ي ايبارا?ـ كراوينكلر استفاده شده است. در ادامه، صحت نتايج به‌دست‌آمده با مقايسه‌ي منحني بارافزون و متناوب از عمليات آزمايشگاهي و روش مذكور ارايه شده است. نتايج اين مطالعه، كارآيي روش مذكور را درتعيين رفتار اتصال با ورق‌هاي فوقاني و تحتاني نشان مي‌دهد.

Major earthquakes that have occurred in recent years have shown that beam to column connections are the main focus in lateral force transference in steel moment frame structures. Over the past years, much research on the seismic behavior of steel moment connections has been performed in order to determine the behavior of joints. Studies agree that in frame analysis, joint rotational behavior should be considered. This is usually done using the moment–rotation curve. Models, such as analytical, experimental, mechanical and numerical, can be used to determine joint mechanical behavior. The most common is the mechanical model, with several variances. In this study, a summary is given on each model characteristic. In this paper, the seismic performance of an I-shaped beam to box-column steel connection with top and seat plates was studied using the component method. In the context of the component method, whereby a joint is modeled as an assembly of components and rigid links, concentrating on beam-to-column and beam-to-beam joints, several components contribute to the overall response of the connection. Despite the complexity of the various connection types, the proposed model is able to provide analytical solutions for the moment–rotation response of a steel connection using appropriate transformation criteria for the assembly of components in series and/or in parallel. Also, in order to evaluate the behavior of the connection in a vast range of nonlinear behavior, a modified Ibarra-Krawinkler deterioration model is used. The correctness of results was examined by comparing the moment-rotation and force-drift curves of the beam to column connection with the top and seat plates, which were obtained by the component and experimental methods. Results show that moment-rotation and force-drift curves obtained by the component and experimental methods are reasonably close to each other; proving the correctness of the above method in evaluating the seismic performance of the connection.