4 ms·

While seat belts work, I think what saved these kids lives were the crumple zones. Those do work twice. If the car crumples in areas that don't impact the rider

by Kequc 10y ago

While seat belts work, I think what saved these kids lives were the crumple zones. Those do work twice. If the car crumples in areas that don't impact the riders that's a good thing. Nobody would have survived such a crash in a classic Chevy. The front of that car is obliterated, but notice the damage ends where the cabin begins. New autos have been receiving upgraded crumple zones for decades because they work. And it looks like Tesla hasn't avoided the issue.

dsfyu404ed 10y ago
I don't know exactly where the hard parts (cabin) of the Tesla begin and end but it's possible to have enough energy to just barrel right through the crumple zone. Crumple zones are directional, when you tweak them they lose effectiveness in their primary direction, that's part of why modern cars get totaled by less damage (your insurance doesn't want to pay big $ for medical when you crash again, with less effective crumple zones). The #1 purpose is to buy time for the airbag to explode before the occupant's faces are occupying the area it takes up once inflated. Acting as an energy absorbing barrier is second priority. It's perfectly possible to hit something hard enough that you only get the first functionality out of it. e.g you hit a brick wall so hard that the "oh the front of the car stopped quick, better explode now" logic has time to happen. Even at 100+mph, the time it takes to drive 4ft (the length of the hood) there's plenty of time for the airbag to explode. However, if the car is moving fast enough the "crumple zone" won't slow the car considerably. Imagine the difference between falling out of a second story window into a (freshly plowed) snow bank vs falling out off the empire state building into the same snow bank, sure it still decelerates you but not enough to matter. Based on the spot where the car wend airborne, it wouldn't surprise me if the crumple zone was tweaked making it easier to completely go though.

by Kequc 10y ago

dsfyu404ed 10y ago

I don't know exactly where the hard parts (cabin) of the Tesla begin and end but it's possible to have enough energy to just barrel right through the crumple zone. Crumple zones are directional, when you tweak them they lose effectiveness in their primary direction, that's part of why modern cars get totaled by less damage (your insurance doesn't want to pay big $ for medical when you crash again, with less effective crumple zones). The #1 purpose is to buy time for the airbag to explode before the occupant's faces are occupying the area it takes up once inflated. Acting as an energy absorbing barrier is second priority. It's perfectly possible to hit something hard enough that you only get the first functionality out of it. e.g you hit a brick wall so hard that the "oh the front of the car stopped quick, better explode now" logic has time to happen. Even at 100+mph, the time it takes to drive 4ft (the length of the hood) there's plenty of time for the airbag to explode. However, if the car is moving fast enough the "crumple zone" won't slow the car considerably. Imagine the difference between falling out of a second story window into a (freshly plowed) snow bank vs falling out off the empire state building into the same snow bank, sure it still decelerates you but not enough to matter. Based on the spot where the car wend airborne, it wouldn't surprise me if the crumple zone was tweaked making it easier to completely go though.