Numerical and analytical investigation on the moment and deformation capacity of interior slab-column connections without shear reinforcement

Abstract

In this study, nonlinear finite element analyses of reinforced concrete interior slab-column connections were performed to investigate their punching shear behavior under gravity and lateral loads without shear reinforcement. A numerical model based on the concrete damaged plasticity (CDP) model in ABAQUS was developed with suitable constitutive models for concrete and reinforcements using eight-node brick elements with reduced integration and three-dimensional truss elements, respectively. The model was calibrated in comparison with the test results of an interior slab-column connection without shear reinforcement. Moreover, the validity of the calibrated model was verified using other test results. Then, a parametric study was conducted to examine the influence of different design variables on the unbalanced moment and deformation capacity of slab-column connections. Finally, based on the existing experimental data and finite element analysis results obtained in this work, formulas for calculating the ultimate unbalanced moment and drift ratio were proposed using the nonlinear fitting method. The proposed formulas were compared with the existing methods provided by other national codes and researchers, verifying the rationality of the proposed formulas.