A New Car Body Architecture

This work was executed by my team as a technology demonstration project for Alcoa's Automotive Business unit in support of a US car manufacturer. The customer had developed a unique 16 cylinder engine that he wanted to showcase in a concept car at the Detroit's North American International Auto Show and my company wanted to show a unique and different way to use aluminum in automotive body structures. Thus we went about to design and build the car below that accomplished both partner's goals.

We wanted to demonstrate use of different aluminum products forms (extrusions, castings, sheet and plate and aluminum based composite using non-traditional design architecture to achieve a lightweight body with minimum number of components, thereby minimize the impact on body's cost, while showcasing the partner's engine. The design had to encompass the look developed by the car manufacturer's design studio and the desired spaciousness and feel of a large luxurious automobile. We also agreed to demonstrate, at least via analytical means, that the new design body had the performance characteristics similar to their current production vehicle. We accomplished this by using an architecture mimicking a mammalian skeletal structure (see graphic below). This was made possible by two enabling manufacturing technologies - first use of large weldable castings and second hydro-forming of extrusions.

We envisioned the front dash and rear seat back panels of the car body as the shoulders and pelvic bones and the center tubular tunnel as the spine - making up the main structure from which the front and rear beams extended out like the arms and legs in a skeleton. To this main structure we added the rocker beams and the requisite hinge pillars for hanging the doors and the roof support beams. We filled-in the space between the rockers and the tunnel with floor composite panels made of aluminum sheet / aluminum foam and the skinned the roof to enclose the cabin. Of course required elements for power-train and suspension attachment were also added and the body was skinned with fenders, hoods, rear deck and bumpers. In the final analysis we had a beautiful car body to show case the engine and fulfill the studios vision for such a luxury automobile. It was accomplished for a weight similar to that of a smaller steel, traditional design, production body. We demonstrated to the partner, via FEA, that this aluminum body had the stiffness and strength of the surrogate steel body. The concept car was shown and won the best-of-show award that year.

The project was an example of participation, cooperation and sharing of knowledge between experts from both partners and was deemed a success.

To see the resume of the expert associated with this case study, see the link below.