Small cars in crashes.

Discuss life, the universe, and everything with other members of this site. Get to know your fellow polywell enthusiasts.

Moderators: tonybarry, MSimon

Post Reply
chrismb
Posts: 3161
Joined: Sat Dec 13, 2008 6:00 pm

Small cars in crashes.

Post by chrismb »

Incidentally, the whole issue of small car safety in actual crashes was addressed by one of our tv channels here, who smashed some little cars into concrete blocks.

The think is, little cars tend to 'bounce' like ping-pong balls, so tend to survive real fast collisions quite well. In fact, they tend to be stronger than their hominid occupants who will experience very high g forces, sufficient to rip out organs and cause death that way. A high mass car into another high mass car will experience less deceleration, therefore such injuries are more likely in smaller cars.

see. http://www.thetruthaboutcars.com/2008/0 ... sh-tested/

But if you go down that logic, then you might equally say that a 3000lbs car is insufficient against a 10,000lbs truck. Where do you stop?

In europe, there have also been a few 'very interesting' accidents between the [arguably] leaders in crash safety, renault cars, versus 4 wheel drive cars. Renaults have been achieving 5 stars in ncap for several years for pretty much all their cars.

In one documented head-on crash between a 2000lbs megane car and a >4000lbs 4 wheel drive vehicle, the megane occupants walked away from their vehicle, while the driver of the 4x4 died as the chassis of his vehicle cantilevered at the stress-raiser between the body and the front of the ladder chassis, bending the vehicle like a banana as it hit the much lighter, but better designed, megane (a car that, in the 1.5dci 80bhp form, has a 81mpg extra urban fuel consumption).

This is why the chrysler voyager scored so badly in the high speed ncap test. This does similarly in frontal collisions. In the NCAP test, the whole of the vehicle split open along the forward bulkhead, leaving the [dummy] drivers legs dangling through the gap.

Giorgio
Posts: 3066
Joined: Wed Oct 07, 2009 6:15 pm
Location: China, Italy

Post by Giorgio »

chrismb wrote:The think is, little cars tend to 'bounce' like ping-pong balls, so tend to survive real fast collisions quite well.
Well, most of those results depend on the kinetic energy absorption system that are implemented into the structure of the chassis itself.
A good car will absorb and distribute the energy of the crash through elastic deformation of the chassis and the reinforcement ribs.
Unfortunately Microcars and most of the Chinese/Indian cars have generally a rigid chassis that will not deform, hence damage to people will be greater.

palladin9479
Posts: 388
Joined: Mon Jan 31, 2011 5:22 am

Post by palladin9479 »

Just goes to show that a well designed small car and beat a big SUV in a crash. I personally enjoy driving smaller cars, not eco cards mind you but just fast and maneuverable automobiles. My constant worry is that some idiot driving by themselves in a large SUV while talking on their phone is going to cause an accident. The whole "SUV's are safer" vs small cars is complete BS. Smaller cars have less kinetic force when they hit something, hence the ping pong scenario, so the only real situation that its advantageous to have a big car is when your in a car on car collision. All things being equal design wise, the more massive object tends to win. This just initiates an arms race in car sizes with each successive generation getting larger and larger to beat out the previous generation. It only ends when we're all driving 3 meter high monster trucks that you see on TV.

ladajo
Posts: 6258
Joined: Thu Sep 17, 2009 11:18 pm
Location: North East Coast

Post by ladajo »

I think you missed the point. As the smaller car ping pongs around, what do you think is happening to the eggs inside?

palladin9479
Posts: 388
Joined: Mon Jan 31, 2011 5:22 am

Post by palladin9479 »

Depends on the angle of the impact. You won't literally ping pong around unless your slamming head on into a concrete wall. And while this is possible and does happen the majority of accidents involve non parallel angles of impact. Getting hit on the side won't produce this effect.

Giorgio
Posts: 3066
Joined: Wed Oct 07, 2009 6:15 pm
Location: China, Italy

Post by Giorgio »

Angle makes difference, but is not the issue.
As ladajo is stating a car during a crash should not bounce to limit damage to the people inside. A perfectly designed car will not bounce at all, but simply stop in the place of the crash with all the kinetic energy being absorbed and transformed in body/chassis deformation.

Any car that bounces more than a small amount is a poorly designed car.

ladajo
Posts: 6258
Joined: Thu Sep 17, 2009 11:18 pm
Location: North East Coast

Post by ladajo »

Yup, that is the point.

Post Reply