Impact of interfacial stresses distribution of structures reinforced by composites FRP: new model of the laminate layers

摘要

This work allows us to determine the interfacial stresses concentrations which are the cause of the debonding phenomenon in the structures strengthened by composites fiber-reinforced plastic (FRP). This method permits to replace the classic techniques based on welding and bolting the elements of the structure that give stresses concentrations to the level of the assembly zone. The technique of reinforcement by patches in composites gives more resistance and rigidity, but it can give stresses concentrations to the edges of the reinforcement zone which can exceed the ultimate loads of the structure and cause failures. In this work, an original interfacial stress theory is developed between the structure and the composite (FRP) and has finalized, taking into account, the mechanical and thermal loads coupled with the shear lag effects. This original method carried out the terms neglected by the previous studies, such as shear lag effect of structure and composites, and thermal load coupled with the model of mechanical and fiber orientation effect. The geometrical and physical parameters taken into account play an important role in the stresses values concentration and thus the phenomenon of delamination