Cyclic Analysis of RC Shear Walls, Considering Bar-Concrete Interaction

In this paper, the nonlinear behavior of reinforced concrete shear wall with consideration of bond-slip effect between the bars and surrounding concrete is investigated. Bar and concrete stress-strain relations, the bond stress-slip relation and the shear stress-strain relation as well as their cyclic behavior including the strength degradation and stiffness degradation are adopted known specifications. In the modeling, shear wall is divided into two types of joint element and RC element. In RC element, the effect of shear deformation is considered and based on Timoshenko beam theory the effect of shear has been considered during the calculation. A numerical model based on the fiber method is used for nonlinear analysis of reinforced concrete shear wall. Separate degrees of freedom are used for the steel and concrete parts to allow for the difference in displacement between the reinforcing bars and the surrounding concrete. The effect of bond-slip has been considered in the formulation of an RC element by replacing the perfect bond assumption from the fiber analysis method. The effects of embedded length and pull-out force on the seismic behavior of a reinforced concrete shear wall were investigated. The reliability of the method has been assessed through a comparison of numerical and experimental results for a variety of specimens tested under cyclic loading. A good agreement between experimental and analytical results is obtained for both cases of strength and stiffness during the analysis.