Its said that cars are “weaker” because they’re now made from a softer material proper to receive impact, thus providing safety to the driver. How will safety work with cybertruck’s 30x ‘ultrahard’ stainless steel when crashing?
In: Engineering
When a car hits something, it’s coming to a very sudden stop and all that energy has to go somewhere. In older vehicles made mostly from steel, that energy usually ended up going into the passengers and cargo, which would cause serious injury. Gradually, cars began to be designed to crumple on impact instead, so the car would absorb most of the energy and the passengers would be less likely to get seriously hurt.
I don’t know how the Cybertruck is constructed but crumpling is only one of the possible ways to get the car to absorb the impact energy. It is possible to use a sturdier material while still achieving the same goal through different physics.
Hard is not the same as tough is not the same as strong.
Cybertruck’s stainless steel body panels are hard; they’re probably also tough, although that’s usually not very relevant for body panels. They’re not any stronger than they need to be though (since that’s what drives weight), so their crash behavior shouldn’t be meaingingfully different.
Hard = how easy it is to scratch. This is obviously really relevant for vehicle body panels, we want them to stay looking nice, harder materials are harder to scratch and stay good looking for longer.
Tough = how easy it is for a crack to grow. Body panels don’t usually crack so this isn’t a big deal. It’s a huge deal for fatigue-critical structure (stuff that goes through a lot of stress cycles) but that’s also not usually a big deal for body panels, they’re mostly decorative and not carrying nearly as much load as the chassis.
Strong = how much stress it can carry without yielding (permanent deformation). Cybertruck doesn’t need to be 30x stronger…it might be 1 or 2x stronger because of the extra battery weight, but nowhere near 30x. That would just be wasted weight, which drives down range and drives up costs, so there’s no reason to do that.
There is probably a difference between the stuff and design used as the energy absorbent crash structure versus the internal frame that has to hold the load of the vehicle. You can absolutely make crash absorbent structures even out of very “hard” material – it is more about the shape than the materials used. Nonetheless, it would seem intelligent to only use the very strong and expensive material for load bearing internal structures and not the “outer” part of the vehicle.
Latest Answers