Assessment of a Glued Aluminum Monocoque and Suspension for Formula SAE® Style Racecars 2000-01-3539

Since 1995, Queen's University has been competing in the annual Formula SAE® competition. The first three formula cars were of conventional construction consisting of a tubular welded steel frame and welded steel suspension components. In the summer of 1997 the team began design and construction of their first monocoque chassis. A technique referred to as cut and fold was to be used for the construction. The material selected for the monocoque was a balsa-wood core with aluminum skins, commonly used in the aircraft industry. An innovative method to produce suspension arms with the use of an adhesive was also developed.

The main objective in the design of the aluminum composite monocoque was to reduce the weight, increase stiffness, and simplify the design of the racecar. During the initial design stages it became evident that the composite monocoque would have many advantages over the steel frame, such as fewer components and the absence of welding.

In order to ensure the design requirements were met, the monocoque and suspension components were thoroughly tested. This included choosing an adhesive that best demonstrated the required characteristics such as high shear and peel strength, resistance to elements and room temperature cure. It was concluded, through testing, that a two-part epoxy would be used because of its strength, safety to users and ease of application. After construction of the first monocoque, torsion tests were performed to assess its integrity. The results were very positive and supported the theoretical design and calculations. The confidence of the Queen's University Formula SAE® Team in the monocoque design incorporated in the 1999 racecar continues to grow. The racecar has endured the 1999 competition as well as a summer of Solo II events with no incidences of failure.