Interfacial stress analysis of steel beams reinforced with bonded prestressed FRP plate

In this paper, a closed-form rigorous solution for interfacial stress in simply supported beams strengthened with bonded prestressed FRP plates and subjected to a uniformly distributed load, arbitrarily positioned single point load, or two symmetric point loads is developed using linear elastic theory and including the variation in FRP plate fibre orientation. The results show that there exists a high concentration of both shear and normal stress at the ends of the laminate, which might result in premature failure of the strengthening scheme at these locations. A parametric study has been conducted to investigate the sensitivity of interface behavior to parameters such as laminate and adhesive stiffness, the thickness of the laminate and the fibre orientations where all were found to have a marked effect on the magnitude of maximum shear and normal stress in the composite member.