Integrating Advanced Composite Materials Into the Chassis of a Sports Car

Abstract

This work evaluated the feasibility of replacing the current stamped-steel floor-pan bulkhead assembly (FBA) of a popular street car with one made of fiber reinforced polymer matrix composite material. To evaluate the feasibility, a finite element model was constructed which incorporated much of the midsection of the vehicle’s chassis. Each part of the chassis section assembly was modeled, meshed, and constrained such that the actual physical assembly relations were upheld. Shell elements were used to model the FBA, and brick and tetrahedron elements modeled the surrounding chassis. Six loading cases were considered: a torsion case, a bending case, and four seat load cases. The chosen composite consisted of an intermediate modulus fiber (AS4) and a typical thermal-set epoxy (3501-6). Four laminate stacking sequences were studied: two quasi-isotropic laminates, a zero-dominated laminate, and a symmetric laminate. A sandwich laminate case was also studied, which utilized quasi-isotropic face-sheets and an isotropic foam core. For comparison a steel case was also simulated. The overall result of the model showed that the sandwich case proved to be superior with the smallest displacements and stresses while reducing weight. The overall weight saving was an astonishing 3% of total vehicle weight which represents a significant savings for an automobile. Based on the results it was determined that the replacement of the steel FBA with a composite FBA is feasible.