Composite Lightweight Automotive Suspension System (CLASS)

The Composite Lightweight Automotive Suspension System is a composite rear suspension knuckle/tieblade consisting of UD prepreg (epoxy resin), SMC (vinylester resin) carbon fibre and a steel insert to reduce the weight of the component by 35% and reduce Co2. The compression moulding manufacturing process and CAE optimisation are unique and ground-breaking for this product and are designed to allow high volume manufacture of approx. 30,000 vehicles per year. The manufacturing techniques employed allow for multi-material construction within a five minute cycle time to make the process viable for volume manufacture. The complexities of the design lie in the areas of manufacturing, CAE prediction and highly specialised design methods. It is a well-known fact that the performance of a composite part is primarily determined by the way it is manufactured. The design team were able to use their extensive knowledge of material behaviour and state of the art manufacturing cells to enable a component that meets the required functional requirements. The CAE optimisation techniques developed during the project made a significant contribution to the project by bypassing a traditional approach and also reducing the amount of physical testing required. This was required to understand the failure mechanisms of the sheer number of combinations of fibre orientations that make the predictive analysis methods viable for a topology efficient design. A compression moulding manufacturing technology was developed capable of mass manufacturing the high strength, stiff and complex shaped suspension knuckle. The processing technology is fully automated, achieving a cycle time below 5 minutes.