Strengthening of Beams by Plate Bonding

At Luleå University of Technology, Sweden, research has been carried out in the area of plate bonding, i.e., the problems that can arise when concrete members need to be strengthened using epoxy-bonded plates. Both comprehensive experimental and theoretical work have been done. In this paper a derivation of the shear and peeling stresses in the adhesive layer of a beam with a strengthening plate bonded to its soffit and loaded with an arbitrary point load are presented. The results from both theory and finite-element analysis show that the stresses are very large at the end of the plate, but they quickly diminish as we move nearer the center of the beam. The magnitude of the stresses is influenced not only by the geometrical and material parameters of the beam, but also by the adhesive and the strengthening material.