Abstract
Keywords: Chassis Torsional Stiffness, Modes of Vibration, Chassis Deflection, Finite Element Analysis, Beam Elements
Through simulation and testing, the objective of this report was to determine the methods and validate results for using an engine as a structural member of a Formula SAE race car chassis. Modal analysis was used with a beam mesh of the chassis to validate an increase of chassis stiffness. Results confirmed that providing structural support at engine mounting points of the chassis increased the stiffness and changed the first elastic mode of vibration from bending to torsion. Additionally a static analysis was used to measure chassis deflection, and established a decrease in deflection when structural support was provided at the engine mounting points of the chassis. This report's conclusion indicates that using the engine as structural member significantly improves the stiffness of the chassis. Furthermore, with improved software Dynamic testing on the frame and engine block should be analyzed to obtain measurable results, establish the allowable forces on the engine and the direction of their application.
The chassis under investigation for torsional stiffness is from The University of Western Ontario's Formula SAE race car. Chassis stiffness can be divided into two components - torsional and bending - critical for the formula race car. Defining the system's axis, a stiff chassis opposes rotation about the y-axis in bending, and twisting about the x-axis in torsion.