Kinematic rigid plastic model for prediction of flexural response of RC beams including shear deformations

In this paper, an analytical model to determine the flexural response under four-point bending tests of simply supported RC beams failing in flexure and shear is presented. The model can provide the load-deflection curves, also including shear deformation; the latter is determined assuming a kinematic rigid plastic model able to consider strength contributions due to dowel action and transverse reinforcements with progressive yielding. For each contribution, a physical explanation is provided to link the strength contribution to a specific kinematic evolution of the overall response of the RC beam under combined shear and flexural loads. The nonlinear FEM software ABAQUS is also used for numerical analyses and comparison between the analytical model and available experimental results. Finally, an extensive numerical parametric analysis in comparison with the analytical predictions is made to check the reliability of the simplified proposed model, also in predicting the complete flexural response of beams including shear deformation contributions.