Topology Optimization of a Formula SAE Upright Using OptiStruct

Formula SAE is a very competitive event in which collegiate engineering teams design, build, and race open-wheeled vehicles. With teams representing the best engineering programs from around the world, small decreases in weight on every component can mean large overall decreased weight for the entire vehicle, leading to faster lap times. The goal of this work is to redesign a wheel upright for a Formula SAE racing vehicle. Being that the vehicle uprights are considered un-sprung weight, any weight savings achieved on their design is worth twice as much as weight savings achieved on sprung vehicle weight. The structural design optimization problem is expressed in terms of two conflicting objectives: minimize the compliance and minimize the weight of the component. The optimization process is performed through a topology optimization approach. Given the loading conditions, tractions, and null elements for the manufacturing of the wheel upright, a new topology is generated. Altair Engineering's OptiStruct software package is used to perform the optimization process. The optimized structure exhibits a 0.31 lb (15%) reduction in mass with no gain in peak stress and practically the same compliance (or stiffness) with respect to the current design. The technique shown in this work can be implemented for other components to decrease the un-sprung weight of the vehicle.