A Developed Flexibility-Based Beam Column Element for Nonlinear Analysis of Reinforced Concrete Seismic Resisting Frames

Abstract

A flexibility-based reinforced concrete beam column element is developed to study the nonlinear static and dynamic response of reinforced concrete seismic resisting frames. To model beam to column flexible connections and rigid zones that formed from beam to column intersections, end springs and end offsets are included in the element formulation, respectively. The element flexibility matrix is formed by integration of in-span section flexibilities using conventional force relations using the Simpson's method. Each cross section in the element span is subdivided into concrete and steel fibers/layers with the assumption of linear strain distribution over the section depth. The effects of shear and bond slip are neglected in the element formulation. The formulated beam column element is implemented into a developed finite element program. For the sake of verification, a series of correlations studies against members and structures available in the literature subjected to either monotonic or cyclic loads were investigated and showed a good accuracy. The proposed element can be used in nonlinear static and dynamic analysis of seismic resisting systems.