impact attenuator

[asahu]

hello,
i m from a new team
please anyone could tell me how to do the calculation of impact attenuator.
we have planned to use poly urethane foam in this.
according to the rules it says that a car of mass 300 kg moving at a speed of 7m/s crashes.then the impact attenuator must sustain a decceleration of 20g.
i dont have any information how to analyze it.

[asahu]

hello,
i m from a new team
please anyone could tell me how to do the calculation of impact attenuator.
we have planned to use poly urethane foam in this.
according to the rules it says that a car of mass 300 kg moving at a speed of 7m/s crashes.then the impact attenuator must sustain a decceleration of 20g.
i dont have any information how to analyze it.

[Pete M]

You need to know the material properties of what you intend to construct your crush zone out of. You can either do this using manufacturer's data or do physical testing yourself. From then on it's basic calculations that you're unlikely to get help on around here. Pick up a textbook.

[vandit]

sahu

the first rule of discussing on forum is to search what u want...there is always possibility of your doubt been already discussed earlier

[asahu]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Pete M:
You need to know the material properties of what you intend to construct your crush zone out of. You can either do this using manufacturer's data or do physical testing yourself. From then on it's basic calculations that you're unlikely to get help on around here. Pick up a textbook. </div></BLOCKQUOTE>
sir
i have got some of the properties of the poly urethane foam
but i am not sure how to test it os per the rules supplied

[Mike Hart]

Polyeurethane foam will disintegrate on contact. Absolutely useless stuff for impact structures. Try a more ductile material rather than something that will just break up on contact.