How do airbags work?????????????????????...

Freight_Train

Here is the Perfect Website for you to check out,
http://www.chemistry.wustl.edu/~edudev/LabTutorials/Airbags/airbags.html

It discuss the Chemistry of how an airbag works.

Once the electrical circuit has been turned on by the sensor, a pellet of sodium azide (NaN3) is ignited. A rapid reaction occurs, generating nitrogen gas (N2). This gas fills a nylon or polyamide bag at a velocity of 150 to 250 miles per hour. This process, from the initial impact of the crash to full inflation of the airbags, takes only about 40 milliseconds (Movie 1). Ideally, the body of the driver (or passenger) should not hit the airbag while it is still inflating. In order for the airbag to cushion the head and torso with air for maximum protection, the airbag must begin to deflate (i.e., decrease its internal pressure) by the time the body hits it. Otherwise, the high internal pressure of the airbag would create a surface as hard as stone-- not the protective cushion you would want to crash into!

UCANTCME

Airbags inflate, or deploy, quickly -- faster than the blink of an eye. Imagine taking one second and splitting it into one thousand parts. In the first 15 to 20 milliseconds, airbag sensors detect the crash and then send an electrical signal to fire the airbags.

Typically a squib, which is a small explosive device, ignites a propellant, usually sodium azide.

The azide burns with tremendous speed, generating nitrogen, which inflates the airbags.

Within 45 to 55 milliseconds the airbag is supposed to be fully inflated. Within 75 to 80 milliseconds, the airbag is deflated and the event is over.

lbhietala

BOOF!!

An accelerometer will detect if the vehicle is slowing down very very fast - like more than 3 g's. You can't slow down that fast just with the brakes, but smacking into something can sure do it. Also, the speed sensor has to tell the computer that you're going above a certain speed. Most airbags won't fire at all if you're going below a certain speed, typically about 35mph. Below that speed, injuries are rare and easily prevented with seatbelts.

So, going fast enough to close the circuit and the accelerometer says you're hitting something pretty hard. So it triggers the inflation charge. The inflation charge is essentially a firework that generates a large amount of gas very very quickly, and vents it all into the airbag. The airbag bursts through the container (steering wheel pad or dashboard pad) and inflates to its full shape and pressure. It begins deflating almost instantly, but will hold pressure and volume long enough to cushion all first and most secondary impacts in a typical two-car accident.

I don't know exactly what the inflation charge is - for that, you probably would do well to look on wikipedia.

CwboyBill

Electronic sensors and computer module 'sense' the sudden negative acceleration of the vehicle and send an electric charge to the module attached to the actual airbag, which in turn ignites a chemical mixture of sodium azide and various other ingredients that produces a huge volume of nitrogen -- all within a few milliseconds -- that inflates a nylon bag into your face.
Blink your eyes -- that's how long it takes to inflate the airbag (which immediately begins to deflate after deployment by way of several sewn-in, quarter sized holes).

sess882

you wreck, they pop

spike

sensors pick up vibrations, g-forces, in a crash, and send a signal to the airbag system. the system fills up the airbags with some sort of gas, just in time, so that your head won't smash into the dashboard.

YAY

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