Seismic Behavior Effect of Knee Braced Frames Considering Different Type of Geometry under Non-Linear Analysis

Abstract

The design and behavior of a ductile structural system called a knee-braced moment frame are presented in this paper. The design of this structural system is based on a capacity-design concept that results in ductile behavior. The knee part is a fuse-like component that dissipates energy by the formation of plastic flexural and/or shear hinges at its ends and mid-span, when the building is subjected to severe lateral loads. However, the diagonal brace component, on the other hand, provides the required level of lateral stiffness and remains in the elastic range without buckling at any time. Attempts have been made, in the present study, to investigate the non-linear seismic behavior of Knee-Braced Frame systems for various influencing factors, and to formulate the effects of the number of building stories, the length of the knee element, and moment of inertia of the bending members on the seismic behavior, the drift of the stories, and the failure mode of these systems. Finally, based on the results of the study, some recommendations have been offered for the effective range parameters for the optimal performance of these systems.