Abstract
Tidal turbine arrays have considerable potential in providing a reliable source of renewable energy. Technology limitations are obstructing the fast development of the sector, however, one of which is the lack of knowledge of mechanical properties of submerged composites used to build tidal turbine blades. Composites exposed to water are known to display lower mechanical properties than their dry counterparts. The extent of this reduction usually varies, depending on many parameters, such as the stress applied, the fibres, the matrix, the stacking sequence, the manufacturing route, the water temperature and degree of saturation. Improving the reliability of the composite tidal turbine blade by developing a better understanding of the material’s immersed properties is therefore very important.
In this paper, basalt fibres were selected as reinforcements for the composites instead of the more usually employed glass fibres, as they typically exhibit better mechanical and corrosion properties and are less prone to water ingress. Unidirectional basalt fibre reinforced plastics (UD-BFRP) were manufactured using a novel towpregging tapeline and a powder based epoxy system. This pilot automated towpregging tapeline was tailored for a new epoxy powder based manufacturing route to build large structures, fitting the scope of tidal turbine blade manufacturing.
The objective of this study is twofold. First, it aims to show the superior manufacturing abilities of the towpregging tapeline developed. Secondly, it intends to compare the mechanical properties of two types of commercially-available basalt fibres, once incorporated into a powder-based epoxy composite, in dry and water-aged conditions.