Abstract: This paper focuses on the effect of different aspect ratios i.e. H/B ratio, where H is the total height of the building frame and B is the base width of the building frame, on the seismic performance of the steel frame structure with and without infill. Here, height of the building is kept constant and the base width is varied. In the present study, seven different aspect ratios ranging from 1.0 to 3.75 have been considered for the ten storey steel frame building. Two types of frames are considered for the study, one with similar steel sections for maximum strength required for beam and column and the other with varying steel sections conforming to the strength and serviceability requirements to withstand the specified loading. For this analytical study, ETABS is used and the comparison between the performances of frames with different aspect ratios is made using pushover curves and performance point. It is found that the presence of infill stiffness contributes significantly to the performance of the structure compared to bare frame

Keywords: Aspect Ratio, Pushover analysis, Steel Frame, Type 1 section, Type 2 section.