Effect of FRP Pipe Scaling on its Adhesive Bonding Strength

Polymer-based materials are emerging as a potential substitute for metallic structures in the oil and gas industry. In this context, fiber-reinforced polymer (FRP) piping is one promising application. An important area of the research pertaining to FRP piping is the connection of pipe sections. Challenges associated with the joining of FRP tubular sections are often considerable, which limits more widespread industrial application. Adhesive bonding is emerging as a promising technique to join tubular FRP structures. The ability to maintain undamaged fiber architecture is a major advantage of adhesive bonding technology. In the present study a strength-of-materials as well as fracture mechanics approach was employed in conjunction with the finite element method to investigate the scaling effects on adhesively bonded tubular sections. It was found that the scaling effects in joined FRP pipe may be significant. For certain composite material configurations the analysis indicated a shift of the region of failure from the pipe structure to pure adhesive (cohesive) failure with increasing pipe diameter.