Sound orientated fibres in composites

Purpose and goal

By being able to control fibre alignment, the properties of short fibre composites, in this case on sheet moulding compound (SMC) and carbon fibre SMC, can be tailored such that a wider range of structural parts can be made using this rapidly processed, cost effective lightweight composite material. This project’s goal is was to show that ultrasonic alignment of fibres can be used in manufacturing with SMC material to tailor the alignment of fibres for pressed components.

Expected results and effects

The results showed that through simulations, the frequencies and geometries that result in short carbon fibre (CF) movement by ultrasound in SMC model material with a rheology and fibre concentration similar to that found in commercial CF-SMC, can be identified. Tensile test showed that localised composite properties can be altered using the ultrasound treatment and that it increases the separation of CF from their bundles. Automotive parts that could benefit from such tailored SMC system were also identified.

Planned approach and implementation

The project was divided into three main work packages not including project administration and dissemination. In WP2, experiments were be done with chopped fibres in oil to establish the parameters required to achieve different orientation and these were compared to simulations. In WP3 the results of WP2 were applied to unsaturated polyester system commonly used in SMC with different geometry of carbon fibres. The final part in WP4 was on how this can be transferred to the orientation of fibres in a mould and an assessment of the automotive parts in which this would be of interest.