Development of a monocoque formula SAE Chassis using Carbon Fibre Sandwich Panels

Abstract

The work presented here describes a conceptual design for a carbon fibre reinforced polymer (CFRP) monocoque chassis for the Formula SAE (FSAE) team design competition. The finite element analysis (FEA) software ANSYS was used for the structure optimisation. The monocoque structure, which followed FSAE rules, was designed using aramid fibre honeycomb core mat~rial sandwiched between preimpregnated (prepreg) carbon fibre mats. ASTM (American Society for Testing and Materials) standards were utilised for designing the coupon composite laminate. The coupon failure load was verified alongside composite laminate theory. A study confirmed the suitabi lity of the use of certain element types for this application. A number of load cases were considered within a structural analysis. Computational analysis facilitated the minimisation of the weight and increase in the torsional stiffness of the structure. The use of a thicker core in the sandwich coupon was found to be pivotal in achieving this. The final design resulted in a torsional stiffness of 1465 Nm/degree at a total weight of29.5 kg, resulting in a 4 7% increase in torsional stiffness to weight ratio when compared to the previous University of Malta Racing (UoMR) team's spaceframe chassis.