This is the same structure used in extremely demanding applications such as rear walls, pillars and chassis tunnels of supercars like the Bugatti Veyron GS Vitesse, Lamborghini Huracan Performante Spyder and Audi R8 Spyder. These convertible models have a significantly higher structural demand because only the floor/tunnel section provides the chassis with stiffness and stability: there is no roof frame to share the burden. Carbon fibre and foam core sandwich structure in the tunnels and other key structural components gets the job done without adding considerable weight.
In-between two 0.5 mm carbon fibre panels (one in our signature herringbone weave and the other in 2×2 twill weave as visible in the photo), foam is injected to form a sandwich. The sandwich structure maximises strength-to-weight ratio and stiffness. It dramatically reduces the volume of carbon fibre required to achieve the same strength.
When the combined thickness of the 2 skins (the carbon fibre panels) is increased 4 times with the injection of foam in-between, the stiffness increases by 3700% and the flexural strength increases by 920% whilst the weight goes up by only 6%.
The sandwich structure of the Everest shell is made 6.5 times the thickness of the 2 carbon fibre panels.
We may have overdone it.