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While many composite monocoque and semi-monocoque chassis have been built there is very little open literature on how to design one. This paper considers a variety of issues related to composite monocoque design of an automotive chassis with particular emphasis on designing a Formula SAE or other race car monocoque chassis. The main deformation modes and loads considered are longitudinal torsion, local bending around mounting points, and vertical bending. The paper first considers the design of elements of an isotropic material monocoque that has satisfactory torsional, hardpoint, and vertical bending stiffness. The isotropic analysis is used to gain insight and acquire knowledge about the behavior of shells and monocoque structures when subjected to a vehicle's applied loads. The isotropic modeling is then used to set initial design targets for a full anisotropic composite analysis.

The validity and usefulness of low-complexity “fast-turnaround CFD” for motorsports design is investigated using results from three different combined experimental and CFD analyses of racing or high-speed vehicles. Analyses using both wind tunnel experiments and CFD simulations (with commercial software and moderate computing resources) found good agreement in some aspects of interest over a variety of applied situations. Key results were the ability for relatively simple CFD models to consistently predict CL in complex flows within 15-25% of experimental findings, predict the effect of design changes on flow, and accurately show qualitative flow phenomenon. However, CD values were not accurately predicted with the low-complexity simulations. Simulations were run using the commercial Fluent© 6.3 application. Experimental results were performed in the Cornell University 4 by 4 foot wind-tunnel.

The goal of this project was to improve the understanding of various joints available for use in high performance small-scale automotive suspensions. The data and conclusions from this effort can be more widely applied to any instance where positive motion control is required with minimal or controlled levels of friction and compliance. This project involved testing and analysis of a series of mechanical joint samples obtained from the Aurora Bearing Company. The particular joint focused on for the majority of the testing is commonly known as a rod end. Ten different samples of varying materials and construction styles were tested and compared. They were evaluated for both compliance and friction over a range of loads to approximate their behavior under normal use. This data was obtained using an Instron tension-compression machine and a selection of appropriately designed and constructed fixtures.

For many racing teams the use of Computational Fluid Dynamics (CFD) as a design tool could mean a very expensive investment. CFD analysis of the complex separated flows associated with a race car would typically require extensive resources. Through the design of aerodynamics for a Formula SAE race car, this paper illustrates the use of less extensive CFD along with the wind tunnel as a tool that reduces design time. Various meshing techniques are analyzed that do not require extensive computational resources and are fairly simple to implement. The results obtained from these methods are compared to experimental results from wind tunnel tests. For the design of wings the results show that the coefficient of lift can be predicted fairly accurately to within 10% of the experimental value, but the coefficient of drag is not predicted very well. It is also shown that the design of an effective aerodynamics package can be accomplished with these fairly simple techniques.

This paper is taken from work completed by the first author as a member of the 1999 Cornell University Formula SAE Team and discusses several of the concepts and methods of frame design, with an emphasis on their applicability to FSAE cars. The paper introduces several of the key concepts of frame design both analytical and experimental. The different loading conditions and requirements of the vehicle frame are first discussed focusing on road inputs and load paths within the structure. Next a simple spring model is developed to determine targets for frame and overall chassis stiffness. This model examines the frame and overall chassis torsional stiffness relative to the suspension spring and anti-roll bar rates. A finite element model is next developed to enable the analysis of different frame concepts. Some modeling guidelines are presented for both frames in isolation as well as the assembled vehicle including suspension.