Help, its been too long since my Uni days to remember.
You know when you get a sponge, pull it in one direction it shrinks in the other?
I'm sure this property has a certain name, but I can't remember and I can't find it online.
Anyone know?
http://en.wikipedia.org/wiki/Poisson's_ratio
Yes, thats it, thank you.
The interesting bit is when you try and put anything under tension in all 3 axis --- ie: tri-axial stress system
Sponginess
Poissons ratio
The ratio of the volume of chips to fish
Used for assessing chip shops frequented by nerdy french speaking engineers 
also
Tri axial stress defined as
Wife, Mother and Outlaw
yes yes, all very good answers.
I felt like such a muppet this morning trying to explain to someone why when you pull an item (sponge was first thing I thought of as my lecturer used
it to demonstrate the principle) it gets narrower.
So I remembered the sponge, but forgot the actual name of the principle.... good to see my University education wasn't wasted.
[Edited on 7/11/11 by balidey]
quote:
Originally posted by balidey
I felt like such a muppet this morning trying to explain to someone why when you pull an item (sponge was first thing I thought of as my lecturer used it to demonstrate the principle) it gets narrower.
[Edited on 7/11/11 by balidey]
Now look for materiasl that when you pull them, they get fatter - ie a 've Poissons ratio... Very weird.