AutoBLADE

Automated Technology for the Production of Continuously Draped Preforms for Large-Area FRP Infusion Components with a High Aspect Ratio

The utilization of energy from tidal currents offers significant potential to increase the share of renewable energy in the future energy mix. The manufacturing of rotor blades for the tidal power plants required for this purpose is, similarly to the production of wind turbine rotor blades, characterized by a large proportion of manual labor. This particularly applies to the preforming process step, in which a large-area textile preform is produced that is subsequently vacuum-infused with the polymer matrix in a later step. While preforming for small and medium-sized components is generally carried out by compressing bindered textile layers, no automated counterpart currently exists for large-scale components with a high length-to-width ratio (aspect ratio). If preforming for such fiber-reinforced composite components can be automated, both economic and quality-related manufacturing optimizations for sustainable energy generation can be anticipated.

The objective of the research project, to be conducted within the innovation consortium of Leibniz University Hannover, Clausthal University of Technology, and the Technical University of Braunschweig, is the development and investigation of an automated technology for the production of continuously draped preforms for large-scale fiber-reinforced composite infusion components with a high aspect ratio. The novel, fully automated manufacturing process, which will be developed using a technology demonstrator in the form of a rotor blade for tidal power plants, includes the layer-by-layer build-up of a preform through continuous draping of online bindered textile semi-finished products onto complex curved surfaces.

With the help of the functional demonstrator of a draping lay-up head for complex structural components developed in the FlexProCFK project, a new technology for the continuous production of a dry-fiber preform will be developed and investigated. One research focus is the fixation of the fiber textile by means of a sprayed binder applied to the tool mold or the previously deposited textile layer in order to prevent slippage. The lay-up process is adapted to the activation behavior of different binder types, and the influence on the quality of the preform is investigated. Furthermore, the infusion behavior of the preform under the influence of the binder material and quantity is examined in permeability measurements and modeled for use in infusion simulations. In the technology demonstrator under consideration, manufacturing-induced fiber angle deviations and wrinkle formation in the preform represent some of the most frequent causes of failure. Through stereoscopic recording of the fiber structure after deposition, the fiber angles and draping defects in the preform are captured and serve as the basis for a realistic infusion simulation and structural analysis for the characterization of the rotor blade properties. The influence of local fiber angle deviations on mechanical component properties such as strength and stability is investigated through simulations as a function of component geometry parameters and material properties. Through continuous exchange within the innovation consortium, the findings from experimental and simulation-based investigations are efficiently integrated and incorporated into process development to improve preform quality.