Shear effects on flexural behavior of internally prestressed concrete beams

The analysis of reinforced concrete beams subjected to axial and flexural loads is founded on the basic assumption that the axial strains across the section are linearly proportional to the distance from the neutral axis, or any axis that passes through an arbitrarily chosen reference point within the section. However, when there is shearing force acting on the section a biaxial state of stress will exist, and the principal stresses are no longer parallel to the longitudinal axis of the beam. In this paper, a simple analytical model for the incorporation of shear deformations into the flexural analysis of simply supported non-cracked internally prestressed concrete beams is described. The model yields the strains and curvatures, at different cross sections, which are used to find the displacements. When comparing the results obtained using the proposed model with others in the literature, it was found that the obtained values are more conservative.