SEISMIC BEHAVIOR OF INTERNAL REINFORCED CONCRETE BEAM-COLUMN JOINTS: A DETAILED MODELING AND SIMULATION INVESTIGATION

In a Seismic Force Resisting System (SFRS), beam-column joints are crucial structural elements. Failure of these elements may lead to total collapse of a structure. Recent earthquakes have demonstrated that structural systems designed based on current codes of practice are vulnerable to sever damages, mostly due to undesirable performance of joints. In general, design codes do not consider the effects of joint characteristics on the behavior of the structure and treat joints as members which remain elastic during an earthquake. To thoroughly understand the effects of different design parameters on the behavior of beam-column connections in RC structures and consequently on the overall performance of SFRS, a wide range of experiments must be carried out. But prior to a successful setup and conducting any experiments, a theoretical study and numerical simulation is essential. Therefore, having some reliable F.E. models at our disposal plays a significant role in the field of experimental and theoretical research. This paper first explains, in detail, the process for developing a F.E. model for RC beamcolumn connections in the simulation environment provided by ANSYS. Next an attempt is made to study the behavior of RC beam-column joints subjected to seismic forces using the developed model. Finally, the effects of main joint characteristics including ductility, moment capacity ratio, type of loading, ultimate loads, over-strength factors and joint transverse reinforcement are investigated.