Stress analysis of steel beams reinforced with a bonded CFRP plate

The use of carbon fibre reinforced polymers (CFRP) composites to upgrade structures and, in particular, to extend the lives of steel beams has wide applications. An important feature of the reinforced beam is the significant stress concentration in the adhesive at the ends of CFRP plate, where there is a discontinuity caused by the abrupt termination of the plate. In this paper, an analytical solution is presented to calculate the stresses in the reinforced beam under mechanical as well as thermal loads. The solution has been extended by a numerical procedure to CFRP plates with tapered ends, which can significantly reduce the stress concentration. Finite element analysis was employed to validate the analytical results, and a parametric study was carried out to show how the maximum stresses have been influenced by the dimensions and the material properties of the adhesive and the adherends.