بررسي اثر ميانقاب مهندسي در رفتار لرزه ‌يي سازه‌ي فولادي و مقايسه‌ي آن با اثر ديوار برشي، ميانقاب بتني و ديوار جداشده

On the Influence of Engineered Infills on Seismic Behavior of Steel Structures, Compared with Shear Walls, RC Infills and Isolated Infills

به تازگي ميانقابي پيشنهاد و آزمايش شده است كه فيوز لغزشي اصطكاكي در ارتفاع مياني ديوار دارد. نتايج آزمايشگاهي و عددي نشان داده است كه اين ميانقاب ها مقاومت جانبي و شكل پذيري بالايي مشابه ديگر المان هاي سازه‌يي دارند و از اين رو ميانقاب مهندسي نام گذاري شده اند. در اين نوشتار، تاثير اين ميانقاب ها در بهبود رفتار لرزه ‌يي سازه هاي فولادي بررسي و در ادامه، عملكردشان نسبت به سازه هاي با ديوار برشي، يا با ميانقاب بتني ساده و همچنين سازه با ميانقاب جداشده از قاب مقايسه شده است. ساختمان هاي فولادي با تعداد طبقات 1، 3، 5، و 7 سيستم قاب خمشي، براساس آيين‌نامه‌ي ايران طراحي شده‌اند. به منظور مقايسه رفتار لرزه‌يي ساختمان هاي مورد مطالعه، يك قاب از هر يك انتخاب و مورد تحليل تاريخچه‌ي زماني غيرخطي قرار گرفته است. براي مدل سازي قاب‌هاي دو بُعدي و انجام تحليل تاريخچه‌ي زماني غيرخطي از برنامه‌ي 0/7 IDARC 2D Version استفاده شده است. براساس نتايج به‌دست‌آمده، ميانقاب هاي مهندسي با فيور برشي لغزان، تاثير بسيار مطلوبي در بهبود رفتار لرزه‌يي سازه هاي فولادي نسبت به ديوار برشي و ساير موارد مطرح شده دارند.

Infill panels are used in buildings for architectural purposes. It is proven that they change the stiffness, strength and damping of a building, but they are ignored in the analysis and design phases, because of many uncertainties and complications. They have a lack of ductility, which is normally required in earthquakes, and, therefore, scientists have focused on new types of infill panel with high ductility. One of these infills has recently been proposed, which has a frictional sliding fuse at mid-height. This type of infill is called an engineered infill panel, and its high strength and ductility have been confirmed by experimental and numerical research. The strength of engineered infill panels rises by increasing the sliding strength of their fuses, which can be adjusted for different values easily through some bolts. The effects of applying such infill panels are investigated on the seismic behavior of the buildings and compared with regular concrete infills, isolated infills and shear walls. For this, moment frame structures of 1, 3, 5 and 7 story buildings, designed on the basis of Iranian codes, are considered. Then, nonlinear time history analyses are carried out for one frame of each building. IDARC 2D Version 7.0 is applied for the analyses. Five earthquake records, including Kobe, Tabas, Elcentro, Northridge and Manjil, are applied in the analyses and the damage indices of the buildings are compared. The Park and Ang formula is chosen for the damage index. The results show that application of the fused infill panels improves the seismic behavior of the buildings and are superior to other considered elements e.g. shear walls, regular infills and isolated walls.