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Comment by temporalparts | Hacker News Reader

They will be designing the cars with buffers, but if a crash can go through all of that AND damages the single casting chassis, which are a lot stronger, then you should thankful because you'll likely have gotten way more injured with a traditional chassis.

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Damage in a collision is a good thing as it requires energy. Not sure why you say a stronger part will reduce injuries.

Because they’re saying these cast are the inner shell that forms the passenger compartment. If they’re deforming, then they’re deforming into the space where the passengers are, and humans squish much easier that aluminium castings.

Regardless if it’s a unibody or a welded chassis parts of it would be designed to give under stress and parts of it would be designed to hold to protect the driver.

In a bad accident with any BEV i would be far more worried about the battery being compromised than the chassis tho.

Perhaps because the stronger part takes more energy to damage and thus absorbs more?

The point that's being made is-- if there's a certain amount of energy being dissipated in a collision, it's better for things to crumple so that the energy is dissipated over a long time period and the peak accelerations (which damage occupants) are less.

A hypothetical perfectly rigid car that stops instantly in a collision instead of deforming is not safer for the occupants, because suddenly they will be going 40MPH inside a not-moving car.

Absorbs? What does it do with that energy, then? Radiate it? AFAIK it's just stiffer so it will effectively transmit the energy along to the next part in the chain. Eventually, that'll be a human.

I meant the energy will be used to deform the chassis, but perhaps I am over my skis here.

Into heat mostly. It takes quite a bit of energy to deform a lump of metal. You need that energy for force atoms past each other, and the metal gets hot in the process.

So yes, absorbs the energy, then radiates it as heat.

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