A general analytical method for the analysis of interfacial stresses in plated beams under arbitrary loading

Recent developments in structural engineering have demonstrated effective enhancement in strength and performance of reinforced concrete (RC) and metallic beams bonded with a fibre reinforced polymer (FRP) composite or steel plate on their tension face. This technique is now popularly adopted for the retrofitting and strengthening of existing structures. Under applied loading after strengthening, interfacial shear and normal stresses are developed between the adherends in such plated beams due to the transfer of stresses between the bonded plate and the original beam. The combination of these stresses may be responsible for premature plate end debonding failure of the plate from the original beam in a brittle manner. Consequently, many analytical solutions have been developed to quantify these interfacial stresses. However, almost all of these solutions are applicable only to thin plates bonded to the beam and are specific to pre-defined simple loading arrangements, so each solution is commonly only applicable to a specific loading. This paper presents a new analytical solution for the interfacial stresses in a simply supported beam bonded with a thin or thick plate to the tension face. The solution is generic and applicable to beams and plates made of any structural materials within the linear elastic range, in common with almost all previous studies. The novelty of this work lies in the application of the superposition principle so that the simple solution is applicable to any arbitrary loading arrangement. Numerical comparison of the new solution with one of the existing solutions and finite element predictions for three loading cases illustrate the accuracy and applicability of the new analytical solution.