Hybrid composite wires for tensile armours in flexible risers: Manufacturing and mechanical characterisation

With the rising global demand for hydrocarbon fuels, there is a growing need for the oil and gas industry to operate in deeper offshore waters. In this context, the traditional metallic tensile armours in flexible risers pose certain limitations (e.g. weight, corrosion, fatigue damage) in demanding service environments. This paper presents a novel and proprietary hybrid composite wire as an alternative to metallic (carbon steel) wires. The hybrid composite wire consists of an over-braided (Dyneema® (Dyneema is a trademark of DSM) fibres) core, with the core consisting of hexagonally packed composite rods (pultruded carbon fibre and vinyl ester). These hybrid composite wires can provide high tensile strength and stiffness accompanied by low flexural and torsional rigidities, which can easily be tailored by varying geometrical and manufacturing parameters. This paper presents the manufacturing methods used, and the mechanical behaviour of the hybrid composite wires with various configurations.