Study of mwcnts filled toughened epoxy for anchoring composite tensile armours inside the end fitting of flexible riser
Résumé
The use of composite and nanocomposite materials is a growing trend in many industries such as aerospace, automotive, civil construction and energy. For many applications, the attachment between structures for efficiently transferring static and dynamic loads is a difficult problem to solve, especially for products which operate for long periods of time under extreme environments with corrosive fluid and high temperature. In the oil and gas segment, for instance, a common technique used for anchoring the tensile armours of flexible riser within the end fitting is through an embedded epoxy resin since it provides good chemical resistance and stable mechanical performance. Even though, cracks and defects can arise in the epoxy block during operations and end fitting mounting at resin curing step, and such cracks could affect the anchoring performance, in particular for composite armours. In this context, this work deals with the understanding of carbon fibre composite armours adhesion behaviour with an epoxy based matrix filled with multi-walled carbon nanotubes (MWCNTs) with a focus on improving the epoxy mechanical properties and its performance in adhesion. Mechanical characterization tests were carried out with referenced and filled epoxies to evaluate the gain of strength and modulus under tension and compression. The delamination toughness is also characterized in order to evaluate the resistance of the bonding structures. Test results confirmed an improvement in some epoxy mechanical properties and delamination toughness although MWCNTs dispersion may by optimized since some agglomerates were found by SEM analysis.