Nonlinear Analysis of Shear-Critical Reinforced Concrete Beams Using Fixed Angle Theory

Abstract

This paper proposes a solution methodology for the application of the fixed-angle theory to predict the shear response of reinforced concrete (RC) beams subjected to the combined actions of shear and flexure. The proposed solution, based on the fixed-angle theory, takes into account the effect of flexural moment on the shear strength of RC beams and calculates the concrete constitutive relationships by transforming the concrete stresses and strains from the principal direction of concrete stresses to that of the applied stresses. To verify the effectiveness of the proposed solution method, seven shear-critical RC beams were tested and their corresponding experimental shear stress-strain relationships were compared with the predicted ones by using the proposed methodology. Furthermore, the shear strengths of 150 RC test beams, reported in the literature with various shear span-to-depth ratios, steel reinforcing ratios, and support conditions, were compared with the predicted shear strengths obtained by the proposed method and other existing truss models. The results presented in this paper show that the proposed formulation can predict the shear response of RC beams with reasonable accuracy.