Formula SAE Frame Torsional Stiffness Study using FEA

Abstract

The Formula SAE competition has the purpose to stimulate the engineering students to work in teams to develop a concept, design and build small racing vehicles. In this competition, students are motivated to build a high performance car, reliable and with low development cost. The success of the team in the competition is determined with a detailed analysis of all aspects involved. Considering the frame development, some key points must be considered for the structural performance: stiffness, durability, modal and safety response. This papers focus on the stiffness analysis to verify if the frame torsional stiffness is compatible with the respective suspension for the level of performance required. The study was performed using the frame of 2012 Formula SAE from Instituto Mauá de Tecnologia using beam elements to model the frame structure in a FEA (Finite Elements Model) software to simulate the system stiffness. The vehicle mass and CG properties to support the studies were obtained in laboratory measurements. The FEA calculated frame torsional stiffness was then compared to the suspension stiffness using analytical methods, making it possible to assess the compatibility between the frame and the suspension. This compatibility was checked in terms of an objective criteria based on the comparison of the roll stiffness distribution versus lateral load transfer distribution. Finally, these results led to the correct identification of the balance between the stiffness values of the frame and suspension for the vehicle proposed, allowing potential improvements for the frame structure in terms of mass and cost. © 2014 SAE International.