Fiber reinforced polymer in civil engineering: Shear lag effect on damaged RC cantilever beams bonded by prestressed plate

This paper presents a careful theoretical investigation into interfacial stresses in damaged RC cantilever beam with bonded prestressed FRP composites, taking into account loading model, shear lag effect and the prestressed composites impact. These composites are used, in particular, for rehabilitation of structures by stopping the propagation of the cracks. They improve rigidity and resistance, and prolong their lifespan. In this paper, an original model is presented to predict and to determine the stresses concentration at the FRP end, with the new theory analysis approach. This research gives more precision related to the others studies which neglect the effect of prestressed composites coupled with the applied loads. 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 fiber orientations where all were found to have a marked effect on the magnitude of maximum shear and normal stress in the composite member. The numerical resolution was finalized by taking into account the physical and geometric properties of materials that may play an important role in reducing the stress values. This research is helpful for the understanding on mechanical behaviour of the interface and design of the FRP-damaged RC hybrid structures.