Deformation prediction of shear critical RC beams based on a multi-angle truss model

Deformations of reinforced concrete (RC) beams with a low span-depth ratio can be attributed equally to flexural and shear components. The former can be calculated using well-established theories and the latter can be analyzed by truss analogy while the prediction accuracy largely depends on the assumed diagonal crack angle. In existing truss models, the moment-induced flexural drift effect is usually ignored and consequently the angles of diagonal cracks are underestimated. To correct this deficiency, a multi angle truss model is proposed in this paper to predict the variation of diagonal crack angles along the shear span by considering the flexural drift effect. Nine RC beams with different shear spanto-effective depth ratios were tested to verify the theoretical models. Results show that the proposed multi angle truss model can provide a sound prediction of the deformation of shear critical RC beams.