Numerical Modeling of the Monotonic and Cyclic Behavior of Exterior RC Beam-Column Joints

Past and recent seismic events have highlighted undesirable brittle failure in RC frame structures, indicating that a substantial damage may result from beam-column joints in non-seismically designed buildings. This paper presents a numerical investigation on exterior RC joints under seismic loading based on a macro-modelling approach, which employs the “scissors model” to schematize the shear behavior of the joint and the bond-slip of the longitudinal steel rebars at the beam-joint interface. A set of literature experimental tests have been used to develop a model for the estimate of the maximum shear strength and a new multi-linear shear stress-strain law of the joint element. Cyclic analyses have been also performed by implementing the “pinching4” material parameters available in OpenSees, governing the hysteresis rules and pinching effect.