Validation Method of Torsional Stiffness for a Single-Seater Car Chassis

In this paper, the torsional stiffness simulation and validation process for a fully electric Formula Student car are reported. The optimization of the performance and efficiency of the cars affects various aspects of both the powertrain and the car body. Three crucial themes can be identified for the development of the cars: the power maps the inverter uses to manage the electric motor, the aerodynamic kit installed onboard, and the overall weight of the car. In this regard, in fact, it is not obvious that a higher value of chassis torsional stiffness leads to better performance in terms of speed or energy consumption. To achieve the best balance between torsional stiffness and weight, different simulations are needed. In this paper, we report a way to validate the simulation of the torsional stiffness value, reproducing the forces exchanged between the chassis and the suspension system. The forces used to simulate the torsion are obtained from track tests. To achieve the goal, the analysis is conducted with several experimental tests on two different chassis: the 2021 steel frame tube and the 2023 carbon fiber monocoque of the “Sapienza Fast Charge” Formula Student Electric team. The main result of the research presented here has been achieved; the numerical calculation procedure for the stiffness of Formula Student-type frames has been experimentally validated, allowing design modifications and developments to be studied by quickly verifying their influence on the stiffness of the new frame. A realistic comparison was also made between the two frames, the 2021 frame with space-frame technology and the 2023 frame with a carbon fiber monocoque. The results obtained, both in simulations and experimentally, clearly show that the monocoque frame has 350% greater torsional stiffness than the space-frame type. This result was obtained with the two bare chassis having the same weight.