Nonlinear Analysis of 3D Reinforced Concrete Frames Considering Bar-concrete Interaction

In this paper a new method for nonlinear analysis of three dimensional reinforced concrete frames (3D-RCF) under cyclic and monotonic loading is proposed. Each reinforced concrete frame is divided into two types of joint and beam-column elements. The effect of bond-slip has been considered in the formulation of beam-column element. The effect of biaxial flexure and axial load on the cross section is assumed for nonlinear behavior while the effect of tensional behavior of beam-column element is assumed linear. The pull-out effect of reinforcing bar is considered in the formulation of joint elements. Formulation and relevant equations are displacement based upon which a computer program is developed. The reliability of the method has been assessed through the comparison of numerical and an experimental result by achieving of excellent agreement. Also the effect of bond-slip and bar pull-out occurring at joint on the response of RC frames is evaluated by utilizing various analyses.