## Overview As part of the GREEN Formula Student team, this project was a design investigation into the mass reduction potential of the front wing support, the component responsible for transferring aerodynamic and inertial loads from the front wing assembly into the car's chassis. Topology optimization was used to identify efficient load-path structures and evaluate candidate design concepts. This was a simulation study; the resulting concepts were not necessarily manufactured or implemented.

Front wing support component highlighted on the GREEN Formula Student car — The front wing support mounted on the GREEN Formula Student car, and the corresponding FEM model with applied load cases. © Wintermantel

The initial component had a mass of 2.93 kg. Through topology optimization and composite design, the final concepts achieved masses of 0.977 kg (full UD carbon) and 0.225 kg (sandwich structure), representing mass reductions of up to 92%. ## Load Cases Two categories of load cases were investigated to capture the full structural demand on the component. **Aerodynamic pressure (18 load cases, T8.4.1):** A uniform pressure of 1.02 N/mm² was applied in the z-direction across the wing surface, incorporating a safety factor of 1.2 over the original measured pressure of 8.889×10⁻³ N/mm².

Pressure load case applied to the front wing — Pressure load case (T8.4.1) — 1.02 N/mm² applied in z-direction with safety factor 1.2.

**High-speed cornering with inertial effects:** Two symmetric load cases were defined for left and right cornering, combining aerodynamic forces with the inertial effects of the wing assembly at high lateral acceleration:

HSC Right: Fx = −400 N, Fy = +310 N, Fz = −3000 N
HSC Left: Fx = −400 N, Fy = −310 N, Fz = −3000 N

High-speed cornering load case with inertial effects applied at the wing attachment points.

## Boundary Conditions

The upper connection points between the support and the car chassis were fully constrained (Tx, Ty, Tz, Rx, Rz), while the lower connection points to the wing assembly were modelled as revolute joints, allowing rotation about the y-axis. ## Optimization Setup The topology optimization was carried out with the following targets: Objective: minimize total mass Maximum total displacement at the connection points: 10 mm Minimum available mass fraction: 7% of the original mass Maximum allowable stress: 600 MPa

Topology optimization iterations — element density evolving towards the optimal material distribution.

## Results

The topology result defined the principal load paths through the component. These paths were then used to determine the optimal carbon fiber lamination directions, ensuring the fibers are oriented along the actual stress trajectories for maximum efficiency.

Carbon fiber lamination directions derived from the topology optimization — Principal stress directions used to define the carbon fiber lamination angles.

## Design Concepts Two manufacturing concepts were derived from the topology result: **Full UD Carbon (0.977 kg)**

Full unidirectional carbon fiber concept, mass 0.977 kg — Full UD Carbon concept — mass: 0.977 kg

A solid unidirectional carbon fiber laminate following the optimized fiber directions. This concept is simpler to manufacture and represents a 67% mass reduction over the original component. **Sandwich Structure (0.225 kg)**

Sandwich structure concept with 1mm UD skins and 8mm Rohacell 52 IG-F core, mass 0.225 kg — Sandwich structure concept (1 mm UD / 8 mm Rohacell 52 IG-F / 1 mm UD) — mass: 0.225 kg

A sandwich construction with 1 mm UD carbon skins on either side of an 8 mm Rohacell 52 IG-F foam core. This is the lightest concept by a significant margin, achieving a 92% mass reduction, but requires more complex manufacturing and quality control compared to the solid UD solution. ## Conclusion This study demonstrated, through simulation, that topology optimization can provide a data-driven basis for significant mass reduction of the front wing support, from 2.93 kg to as low as 0.225 kg, while satisfying all structural constraints under the full set of aerodynamic and dynamic load cases. The two concepts present a clear trade-off: the sandwich structure offers superior weight performance, while the full UD carbon approach is more practical for a student team environment where manufacturing simplicity is a priority. These results represent design benchmarks and initial investigations; physical implementation was not part of the scope of this work. ## References

SAE International. Formula SAE Rules 2022. SAE International, 2022. Section T8.4.1 — Aerodynamic Device Load Cases.
Altair Engineering. OptiStruct User Guide — Topology Optimization. Altair HyperWorks Documentation, 2022.
Altair Engineering. HyperMesh Reference Manual. Altair HyperWorks Documentation, 2022.
Evonik Industries. ROHACELL 52 IG-F Product Data Sheet. Evonik Resource Efficiency GmbH, 2021.
Bendsøe, M. P., and Sigmund, O. Topology Optimization: Theory, Methods, and Applications. Springer, 2nd ed., 2004.