Pressure in a Door During Side Impact Event...

WHY? I can't think of an worthwile reason to measure the pressure inside a doors during a side impact. New cars will all have side impact airbags. I have never seen a car door 'explode' or show any evidence of significant pressure increase. Al ldoors have bottom water drains which would vent pressure. Also the 'seal' between the door cavity and auto body is very tenuous, and, at most, IF totally sealed, a very thin strechable plastic membrans that would not hold more than a few inches of water pressure--maybe 3-5 inches of water at most.

Answer nuff?

Actually, you would want to know the pressure in a door, if you wanted to use
pressure sensing to sense a side-impact. The door is a cavity that is partially sealed at 15psia. During an impact, the door will get compressed rapidly, causing an impusle response of the pressure inside the door. I'm hoping my cheap-ass MEMS pressure die will work for this application.

wndrtch

are u wanting to know abt side door impact of a pass car (m1) static /dynamic?

Yes, dynamic!

I would like to use my cheap MEMS pressure die for this application. I'm just not sure if the dynamic impusle response is low-psi (0-1 or 2psi) or higher (5+ psi) in range.

The peak pressure can be computed if you know the change in volume and the area of the escape holes, and the rate of change of volume. Use simple orifice flow pressure drop equations and solve the dynamic equation. The result will not be too accurate, but will let you know if it needs further work or not. This is a highly developed science in the aircraft industry where every void must survive explosive decompressions, for instance from a door coming off.

I'd like to follow this as side impact is usually the one that causes brain injury and death. Any research in this area has to be good, and i don't see that many cars on the road with side air bags!

Here in the States, the Government is moving to mandate side airbags in all cars. Proposals have been made, but not implemented as law yet. The main impediment seems to be cost (what isn't) for the electronics. I've read where automakers are looking into pressure sensing technologies (MEMS) as a possible way to reduce costs and make these systems affordable for the mass market autos.

wndrtch

I'm all for things that help save lives, but tell me, is the wearing of seat belts compulsary in the states?

It depends on the State. Here in Mass, it is law to wear your seatbelt, but it is not a "Primary" offense, which means the cop has to stop you for another infraction, then can charge additional penalties (I think its $50 per occupant not belted).

For me, it's an issue of Natural Selection, so I wear mine at all times.

wndrtch

I'm with you on that, in fact, anything less then a 5 point harness makes me feel insecure in a car these days. just bwhat you get used to.