Nonlinear finite element analysis of reinforced concrete beams failing in flexure

Reinforced concrete (RC) members are designed to have shear strengths much greater than their flexural strengths to ensure the flexural failure according to the current design codes. Flexure failure in beams starts with the flexural yielding and the shear degradation in the lateral load capacity occurs due to damage related to flexural deformations. Because of the complexity of shear-strength degradation, Seismic Codes tend to be excessively conservative and does not take into account the contribution of concrete in certain cases. The research conducted in thesis proves numerical information about the effect of flexure on the shear degradation of RC beams. An analytical equation reflecting the reduction in concrete contribution to shear strength is investigated. It is also observed that the contribution of concrete to the shear strength is decreased by an increase the displacement ductility and the ratio of the shear strength to transverse load capacity calculated from flexural capacity.