New algorithm for fixed-angle softened-truss model

The present paper proposes a solution methodology to predict the shear stress–shear strain curves of reinforced concrete (RC) elements (panels) using a truss model. The proposed solution procedure calculates the concrete constitutive relationships by transforming the concrete stresses and strains from the principal direction of concrete stresses to the principal direction of the applied stresses. As a result, the algorithm predicts the shear responses of RC elements having a large difference between the amounts of steel in two perpendicular directions. To check the success of the proposed methodology, the experimental shear stress–strain and shear stress–normal strain curves of 12 RC elements as well as the shear strengths of 170 beams reported in the literature are compared with their corresponding predicted results using the new algorithm of the truss model. The results show that the proposed algorithm accurately predicts the variation of the concrete strain of 12 reinforced elements and the shear strength of 170 beams.