اثر ورق نازك فولادي پُركننده در رفتار مهاربند واگراي هشت

Effect of Filler Thin Steel Plate on the Behavior of Chevron Eccentrically Braced Frames

مهاربندهاي واگرا به‌دليل ‌داشتن هر دو مزيت شكل‌پذيري و سختي مناسب، از دهه‌ي 70 ميلادي مورد توجه پژوهشگران قرار گرفته‌اند. همچنين ديوار برشي فولادي نيز به دليل مزاياي عمده‌ي رفتاري، بيش از 4 دهه است كه در طرح و تقويت ساختمان‌ها به‌كار گرفته مي‌شود. در اين نوشتار سعي شده است رفتار تركيبي اين دو سيستم در سه حالت وجود ورق‌هاي كناري، وسط و كل دهانه و با ضخامت‌هاي مختلف ورق، پارامترهاي رفتاري سيستم مورد بررسي و مقايسه قرار گيرد. نتايج حاكي از افزايش جذب انرژي، مقاومت، سختي، شكل‌پذيري و ضريب رفتار سيستم نسبت به حالت مهاربند واگراست. در ادامه، نيز روابط تحليلي براي طراحي اين سيستم تركيبي ارايه شده است.

Since the seventies, eccentrically braced frames have been considered by researchers because of having both advantages of appropriate ductility and stiffness. Yet, the steel plate sheer wall is still being used for many behavioral benefits in the design and reinforcement of buildings. In this paper, the dual behavior of these two systems, and the behavioral parameters of the systems in three forms, including; side plates, and middle and whole spans with different thicknesses of frame, were studied. The results showed an increase in energy absorption, strength, stiffness, ductility and higher behavior coefficient of the system in comparison with the braced frame. In the rest of the paper, analytical relations for the design of the system are presented. The modeling is done for different positions of the filler plate in eccentrically braced frames, and the models were analyzed. The analyzed models include three positioning forms for the filler plates. Each form was studied and compared for three thicknesses; 0.5, 1, and 2 mm. After analysis and obtaining the results regarding system thickness, the thickest dual system is always related to the form of three panels filled by plates. Finally, we achieve three formula for computing the thickness of the dual systems in all three forms. In the case of ductility between different forms of dual system, regardless of plate thickness, the best ductile system is for two side panels filled by plate. In the other forms, considering plate thickness, the best ductile system is for two side panels filled by 0.5mm plates, whose behavior coefficient is 9.01, while the behavior coefficient of eccentrically braced frames with out plate. In all forms, the ultimate strength of the dual system is greater than the eccentrically braced frame without plate, and most of the time, dual systems have more energy absorption than it does.