Challenges in Joining Thermoset Composite Piping

The aim of this paper is to examine solutions and challenges related to joining thermoset composite piping. Fiber reinforced polymers (FRP) have been used in piping systems for more than 40 years. Higher specific mechanical properties and corrosion resistance of FRP make them a potential candidate for replacing metallic piping structures. Despite the advantages associated with FRP, their application is still limited due to, in part, unsatisfactory methods for joining composite subcomponents and inadequate knowledge of failure mechanism under different loading conditions. Adhesively bonded joints are attractive for many applications since they offer integrated sealing, minimal part count and do not require pipe extremities with complex geometries such as threads or bell and spigot configurations. So far, the majority of work reported in the technical literature on adhesively bonded pipe joints is concerned with lap joints employing wrapping techniques to produce overlap sleeve connections. More recently, a joining technique was proposed that replaces the wrapping technique with filament-wound overlap sleeve couplers that are adhesively bonded to the pipe extremities. In the present article, various joining techniques for FRP piping through adhesive bonding are discussed, and damage mechanisms under different loading conditions are examined.