Effect of shear deformation on interfacial stress of fiber-reinforced polymer plate–strengthened reinforced concrete beams

Abstract

For fiber-reinforced polymer–strengthened reinforced concrete beam, one of the major failure modes is debonding failure. The premature failure led to the rapid development of analytical solutions on interfacial stresses. Existing analytical solutions usually fail to consider the effect of shear deformation in the adherends completely. In this study, a new theoretical solution is proposed based on Timoshenko beam theory. The coupled governing differential equations of interfacial stresses are solved by weighted residual method based on the least squares principle. The effect of shear deformation on both interfacial shear and normal stresses is obtained simultaneously with relatively simple expressions of interfacial stresses. Moreover, the proposed solution is compared with other previous solutions to further validate the effect of adherend shear deformation on interfacial stresses. Overall, the parametric study demonstrates that the thicker adhesive layer, thinner fiber-reinforced polymer, or lower fiber-reinforced polymer modulus would effectively reduce the peak interfacial stresses at the fiber-reinforced polymer plate end.