Elastic analysis effect of adhesive layer characteristics in steel beam strengthened with a fiber-reinforced polymer plates

In this paper, the problem of interfacial stresses in steel beams strengthened with a fiber reinforced polymer plates is analyzed using linear elastic theory. The analysis is based on the deformation compatibility approach developed by Tounsi (2006) where both the shear and normal stresses are assumed to be invariant across the adhesive layer thickness. The analysis provides efficient calculations for both shear and normal interfacial stresses in steel beams strengthened with composite plates, and accounts for various effects of Poisson's ratio and Young's modulus of adhesive. Such interfacial stresses play a fundamental role in the mechanics of plated beams, because they can produce a sudden and premature failure. The analysis is based on equilibrium and deformations compatibility approach developed by Tounsi (2006). In the present theoretical analysis, the adherend shear deformations are taken into account by assuming a parabolic shear stress through the thickness of both the steel beam and bonded plate. The paper is concluded with a summary and recommendations for the design of the strengthened beam.