A Numerical Study on the Seismic Response of RC Wide Column–Beam Joints

Reinforced concrete (RC) column–beam joints are one of the most critical elements in RC structures which have a big impact on the seismic response of structures under different loads. To investigate the effect of beam and column dimensions on the seismic behavior of RC wide column–beam joints, 27 numerical models were created using nonlinear finite element method (FEM) software. Displacement-control condition was applied to the top surface of columns in all of the models and boundary conditions and material properties were considered the same as the experimental model. Three numerical models were verified by similar experimental study. The other models were changed in width and depth to find the effect of dimension changes on the displacement ductility and curvature ductility by evaluating force–displacement and moment–curvature diagrams. In general, it could be concluded that by increasing the ratio of beam width to beam height, displacement ductility of RC joint and curvature ductility of beam increase. Moreover, based on the FE analysis by increasing the ratio of column width to column height, displacement ductility increases, while curvature ductility decreases. Results also indicated that increasing the area of column section could lead to increase in displacement ductility and decrease in curvature ductility of RC wide column–beam joints. In addition, the influence of mesh size on the analytical outcome of FE analysis was also investigated. After evaluating the results, equations for estimating seismic parameters, displacement ductility and curvature ductility, in RC wide column–beam joints were suggested.