01 What
The previous-year chassis (EXO4) wasn't stiff enough, causing the monocoque to act as an unintended third spring between the front and rear suspension. I derived a torsional stiffness target from lap-time simulation and suspension/driver input, then validated the new design against it through FEA.
02 How
- 01Derived the stiffness target by weighing lap-time gains against the mass penalty of a stiffer structure, informed by suspension-department and driver feedback.
- 02A 0.8% mechanical-balance tolerance set the minimum target at 7,000 Nm/°.
- 03Built the monocoque FE model in Altair HyperMesh, applied the torsion load case, and extracted deflection to calculate stiffness.
03 Result
- —Raised torsional stiffness from ~4,000 to 7,020 Nm/° (+75%), while mass increased by only 35%.
- —Correlated the FEA prediction against the team's prior-year physical test bench data to within ±150 Nm/° (~2% error).
- —Delivered within all constraints, including a frame mass target under 23 kg.
