Modeling of shear behavior in reinforced concrete beams

The purpose of this paper is to develop a reliable two-dimensional (2D) finite element (FE) modeling approach for the nonlinear behavior of reinforced concrete (RC) shear-critical elements. The proper kinematic field is achieved by using different finite elements for the concrete, the steel, and the steel-concrete interface; separate constitutive models are formulated for each type of material. A modification of the 2D strength envelope of concrete in plane stress is proposed to consider the effects of triaxial stress conditions in beams with small shear span-to-depth ratio. This approach allows successful comparison with experimental results on RC beams for a significant range of design parameters, load conditions, and reinforcement arrangements. Finally, a critical review of several modeling approaches in the literature is carried out.