Topological Optimization of a Formula Student Monocoque Chassis with Fixed Torsional Stiffnessand Element Size Influencein Ansys

The SAE (Society of Automotive Engineers) through its formula competition proposes the development of a complete competition vehicle in order to encourage the project in addition to new techniques in this area of study. Within the vehicle’s subsystems, there is the chassis being of great importance for the vehicle’s dynamic performance in addition to coupling all other subsystems. Therefore, the present work aimed to develop a new monocoque chassis geometry through a topological optimization made in Ansys. An initial geometry of the author himself was used when he participated in a competition team. From this geometry, a static analysis was generated to measure the deflection that influences the torsional stiffness of the chassis, this analysis being the limits or boundary conditions of the imposed minimization problem. With an element size analysis of 15 mm, 20 mm and 25 mm it was possible to define that the smaller size produced better results and the following results were obtained in this condition. Through 27 iterations, it was possible to reduce the mass of the structure from 157.89 kg to 129.16 kg, which means a 19.2% reduction in mass without changing the torsional stiffness value of the chassis. A new design of the geometry was made based on the optimization with a reduction of approximately 10% of the mass, due to the restrictions of the manufacturing processes for material removal for 15 mm element size and 11% for 20 mm and 25 mm. From the analysis it was possible to infer that the software was practical and useful in the process of topological optimization of the chassis for a competition vehicle, prioritizing mass reduction and increased performance on the track and that a small element size does not always produce the best feasible material reduction.