Executive Summary : | Fibre Reinforced Polymer (FRP) composite materials have been used for construction for the last few decades. FRP consists of high strength fibres like glass or carbon embedded in a resinous matrix. They offer various desirable properties for civil engineering applications such as high chemical and corrosion resistance, durability, lightweight and higher speed of construction. Pultrusion is the cheapest manufacturing technique for FRP structural profiles. Standard pultruded FRP profiles resembles structural steel profiles. Glass fibre is commonly used as the reinforcement due to their relatively lower cost and better performance compared to other fibres. Bolting and adhesive bonding are the commonly used connection types in FRP structural members. However, hybrid joints combining bolted and bonded connection could lead to more efficient load bearing from different directions and enhances the long-term performance and fatigue life. In the present study, design guidelines are proposed for hybrid beam to column joints in FRP and steel. Two types of joints between FRP beam to FRP column and FRP beam to steel column are analysed. The parameters considered in the study are type of connection, loading type and type of cleats used. Bolted and bonded hybrid connections are analysed to evaluate the effectiveness of bonding in the joint behaviour. The energy dissipation capacity of the joints under both monotonic and cyclic loading is evaluated. The performance of joints using steel cleats and replacement of steel cleats using equal stiffness FRP cleats are to be evaluated. Distinction between FRP and steel cleated joints are analysed and design guidelines are developed. The performance evaluation of the joints is done based on the ultimate load capacity, ductility, energy dissipation capacity and failure modes. The study also aims to utilise the semi-rigidity of joint to offer design flexibility to structural system. The effectiveness of the hybrid structural system is done by conducting the studies on both exterior and interior beam to column joints. Design guidelines are developed for ultimate strength and serviceability criteria of the joints. |