Front wing mainplane for an open-wheel racing car: design exploration and optimization of its inner structure

This thesis presents the structural optimization of an open-wheel racing car front wing mainplane, carried out during a six-month internship at Dallara Automobili. The goal of the project is to enhance the stiffness to mass ratio of the assembly by optimizing the inner structure of the mainplane, focusing on the spars. The work is performed in the digital domain, using PTC Creo and Ansys students as main tools. The study begins with the creation of a baseline model of a formula front mainplane assembly, where the original and confidential airfoil is replaced with a standard NACA profile, to preserve the design while maintaining validity. The initial design, which features two vertical CFRP spars bonded to metallic inserts and endplates, is evaluated through FEA to determine its stiffness under a standardized test performed in Dallara. This result is the foundation for subsequent optimization. The first phase of geometric optimization is conducted in Creo Simulate using integrated algorithms (SQP and GDP). The spar geometry is varied to minimize the deflection of the mainplane under constant load, exploring the influence of shape and thickness. These can lead to a measurable stiffness improvement of over 2%, with marginal mass increase. After this first step, alternative spar geometries (omega, reversed omega and lightened versions of these) are explored. Among these the reversed omega is the most promising, offering up to 20% stiffness increase with efficient mass usage. In the second phase of the project, the composite layup of the spars is optimized. This is performed in Ansys ACP. Starting from the geometrically optimized designs, different ply orientations and stacking sequences are tested through a Design of Experiment (DOE) approach. The study aims at identifying the most effective fiber orientation to maximize stiffness in the same condition measured before. The results highlight the significant influence of layup configuration of the global stiffness of the mainplane. Finally, a design for manufacturing and cost analysis compares the optimized concepts with the baseline. The study finds that the revered omega design achieves superior performance without gravely exceeding the cost of traditional double spar solutions, benefitting from reduced par count and simpler assembly. This work demonstrates and shows how parametric modelling, FEA and optimization algorithms can be combined to guide design solutions, when the direction to take is not immediate to the designer. This is of extreme value in motorsport, especially in competitive championships where few percentage points can make the difference between a victory and a loss. In a more philosophical way, it shows how important details are to achieve the maximum performance, a concept that can be extended to any endeavor of life.