New end fitting based on bolted joints with composite tubes

Abstract

This thesis contains work on joining the GFRP pipes with metal end fitting. Professor A. Echtermeyer have proposed a concept using bolted connections. Prior to my work Master students K.Dons and A. Fossaa have developed the concept further. My work is to continue improving the end fitting design made by A. Fossa.

The new end fitting design improves the end fitting for the testing purposes. The end fitting designed by A. Fossaa is one piece. By splitting end fitting in two makes it easier to use it as well as it improves geometric parameters. It gives also possibilities to test the pipes with wider range of thickness. The new design has better sealing properties due to new way to use PE liner with the end fitting.

However the end fitting has only been tested in one pressure tests. Still it needs to be tested in tensile and fatigue. As well, because of production limitation all features of the desired design are not produced. The middle flange with bended edge should also be produced and tested.