Design of the Front Upright for a Formula Student Racing Car

Abstract

This report aims to explain the full design and analysis of the front upright -the car component which links suspension wishbones and steering bar with wheels- of the TAU Racing’s 2012 car. The first step is to find the worst load case that might affect the upright. Due to the fact that the study only covers the front ones, the worst load case occurs when the car is cornering and braking at the same time (load transfer effect). Once the loads are studied, the next step is to design the upright and all the components involved in the assembly which will link the wishbones and the wheels. The first problem appears in this point because there is not enough space for all the components. A little change in the suspension geometry (increase of the scrub radius length), solves the problem. The next step is to carry out the bearings life calculations and the finite element analysis (stress and displacements). The results are correct but, after showing to the team leaders the design, another problem appears: the assembly is heavier than expected. The solution agreed is to reduce the bearings size which affects all the assembly. Therefore, another full design is suggested. The bearings life is calculated and the finite element analysis is carried out once again. This time the results are worse: the bearings life is short but, since the competition only lasts a weekend, it is accepted; and the upright has a factor of safety lesser than expected. Hence the last step is an optimization of the upright and, as a result, the factor of safety increases above the minimum required. The overall weight is reduced in almost 20%, twice as much the team goal.