Development of Vacuum Assisted Composites Manufacturing Technology for Wind Turbine Blade Manufacture

Abstract

Wind turbine blade manufacturers employ the vacuum infusion technique to produce monolithic and sandwich cored components, recent innovations have seen companies such as Siemens develop products which incorporate an internal composite structure in a single process (Siemens 2008). This thesis explores the technique of resin infusion and develops a manufacturing process to allow a small wind turbine blade to be manufactured in a single process complete with its internal structure.

An innovative manufacturing method for creating three-dimensional internal structures within composite components is presented. A technique is developed for the production of polymer matrix composite products containing both external faces and internal structures in a single process. The main focus is on the production of small prototype wind turbine blades although the technique is transferrable to other hollow or foam cored composite products.

This work leads to the manufacture of prototype 2.5m fibreglass wind turbine blades and their internal structures in a single process. The technique developed forms the structural spar section as an integral part of the wind turbine blade. Methods of infusing resin within a closed mould environment are developed utilising custom resin channels to control the nature and rate of resin infusion through the structure.

Investigation of a range of core materials used in composites manufacture to improve stiffness, strength and fatigue was explored. A range of specific reinforcement materials and resin systems are tested to determine a suitable laminate structure for blades that complements the vacuum assisted method.

Methods for the manufacturing and fabrication of blade plugs and composite mould tooling are presented with features to facilitate the use of the vacuum assisted manufacturing technique. Equipment and execution of the process is given.

Findings are applied to produce a composite component with internal structure comparable to current manufacturing methods targeted around small wind turbine blade manufacture.

Results conclude that the development of a process to manufacture a complete wind turbine blade in a single process is achievable and feasible. Results and outcomes of the research are presented with recommendations and suggestions for future work.