Modeling of Interior Beam-column Joints for Nonlinear Analysis of Reinforced Concrete Frames

Beam-column connections are often assumed rigid in traditional frame analysis, yet they undergo significant shear deformations and greatly contribute to story drifts during earthquake loading. Although local joint models are available in the literature for the investigation of single, isolated joints, there is a lack of holistic frame analysis procedures simulating the joint behavior in addition to important global failure modes such as beam shear, column shear, column axial, and soft story failures. The objective of this study is to capture the impact of local joint deformations on the global frame response in a holistic analysis by implementing a joint model into a previously-developed global frame analysis procedure. The implemented joint element simulates joint shear deformations and bar-slip effects. Concrete confinement effects are also considered so that both older and new joints can be modeled. The developed procedure provides better overall load-deflection response predictions including the local joint response.M.A.S