POWDER EPOXY BASED UD-CFRP MANUFACTURING ROUTES FOR WIND AND TIDAL TURBINE BLADES

摘要

The potential of ocean renewable energy is tremendous. However, further development of tidal turbine blades is required due to the harsh marine environment, large cyclic forces and high cost of installation. Carbon fibre reinforced polymers are promising materials for marine applications; hence, it is vital to understand fully their material properties and failure mechanisms. The tidal turbine blade processing conditions need to be perfected to ensure a robust and cost-effective design. In this study, a novel powder-based epoxy process, with low resin viscosity and low exotherm, is described. Two manufacturing routes were investigated. Initially, a hand lay-up process, which used a custom tensioning apparatus, was adopted to keep the carbon fibres straight during the thermal cure cycle. Additionally, a powder-epoxy-fed tapeline was developed as a first step to automation. Mechanical properties from both techniques were examined, with specimens from both processes exhibiting autoclave-like properties, which highlights the advantages of the powder epoxy based materials. Hygrothermal ageing of the composites in seawater conditions was also performed. At water saturation (1.23 wt.%), an 11.5% reduction of the failure stress was reported but stiffness was retained. Finally, fatigue testing was carried out to predict the durability of the structure.