Determining of Dynamic Characteristics of Steel Frames with Semi-Rigid Connections by Push-Over Analysis and Nonlinear Dynamic Analysis

Dynamic characteristics of steel structures including flexural frame system with semi-rigid connections are investigated in this study. With this regard, four frames have been modeled including two-span two story, threespan four-story, three-span six-story and four-span eight-story frames. The frames are analyzed and evaluated for variation of the connections stiffness from semi-rigid to rigid and for both cases of push over static analysis and nonlinear dynamic analysis under earthquake acceleration. After that, plastic hinge formation in the frame, frame failure, energy dissipation in members and connections, maximum displacement of stories and frame, base shear force, behavior coefficient, coefficient of design load increased strength have been investigated. The results showed that stiffness increase of connections in the frame, increases the base shear force and coefficient of increased strength, and reduces the period, maximum and relative displacement (drift) and coefficient of frame behavior.