New design for reducing interfacial stresses of reinforced structures with FRP plates

Purpose: The sustainability of the structures is not only a technical goal, but also a matter of social and environmental values. This requires the researchers to use very rigid, highly durable and corrosion-resistant composite structures in order to achieve the technical, environmental and social goals. The purpose of this paper is to present an original work on reducing the interfacial stresses of bonded structures with fibre-reinforced polymers (FRP) plates based on new taper design. Design/methodology/approach: In this proposed concept, the effect of combined taper is investigated on reducing interfacial stresses, attempting to enhance the structure performance and address the debonding problem that comes with reinforcing techniques. This research is carried out by using finite element analysis, incorporating many new parameters. Findings: As a result, a new solution is discovered that combined taper in both adhesive layer and composite laminate, which significantly reduces the interfacial stresses at the end of the FRP plate. Additionally, a parametric study is carried out in order to determine the optimal configurations of taper dimensions as well as other parameters that influence the stress concentration distribution at the edge of the adherends. Practical implications: This new design regarding the reduction of interfacial stresses will help in increasing the lifespan of damaged structures reinforced by FRP composites, preserving thus its technical, historical and social values. Originality/value: The paper uses straight, concave and convex fillets with inverse taper as a new design solution with new parameters including thermo-mechanical loads and pre-stressed FRP plate with multi-layer, fibre orientation and shear-lag effects.