A rigorous solution for interfacial stresses in plated beams

A significant increase in the strength and performance of RC, timber and metallic beams can be achieved by bonding an FRP composite, steel or metallic plate on the tension face of a beam. One of the major failure modes in these plated beams is the premature debonding of the plate from the original beam in a brittle manner. This failure is often attributed to the interfacial shear and normal stresses developed between the adherends, which has led to the development of many analytical solutions over the last two decades. Most of the previous solutions have failed to include the effect of the adherend shear deformation due to difficulties in arriving at the exact solution, although a very few solutions have considered this effect in different approximate methods. The few solutions which included the effect of shear deformation of adherends are limited to one or two specific loading conditions. This paper presents a rigorous analytical solution for predicting the interfacial stresses in plated beams under an arbitrary loading with the axial, bending and shear deformations of the adherends considered simultaneously in closed form using Timoshenko's beam theory. The solution is applicable for any prismatic cross section with any linear elastic material for the adherends and thin or thick plates bonded either symmetrically or asymmetrically to the beam. The present solution is compared with previous analytical solutions.