Use of advanced composite materials in the construction of suspension push-rods for a Formula one racing car

Advanced composite materials, particularly carbon fibre-reinforced epoxies, are used extensively in the construction of contemporary Formula One racing cars because of their high specific stiffness and strength properties. The present Chapter is concerned with one significant load-bearing component, namely the suspension push-rod. These push-rods exist at the four corners of a car and link the monocoque, engine and gearbox casing to a racing track and, as such, they are subject to severe inertial forces and dynamic compressive and flexure forces. The design, manufacture and in-service behaviour of carbon/epoxy push-rods are discussed in the present Chapter. Both uniform and tapered layups of unidirectional and woven cross-ply prepreg have been used to manufacture pushrods of aerofoil cross-sections. These structural components have been loaded to catastrophic failure and the identified damage mechanisms were seen to includefibre micro buckling, fibre kinking and fibre fracture. A comparison has been made between the actual and theoretically predicted failure strains and it is seen that buckling was the ultimate cause of failure in all cases. The ultimate strength of the carbon/epoxy composite material was greater than the compressive strength of the push-rods and consequently, scope exists for improving the performance of the present design of composite push-rods.