Finding Poisson's ratio from rigidity and Young's modulus

[mattjones]

Hi, I'm wondering if someone can point me in the right direction with this question.

A material has a modulus of rigidity of 100 GNm-2 and a Young's Modulus of 250 GNm-2. Calculate the expected value of Poisson's Ratio for the material.

Poisson's Ratio is expressed as transverse strain / axial strain

So how am I supposed to work this out when the only information I am given is what's above? Or am I misunderstanding the question?

Any help would be appreciated

Thanks

Matt

 

[SteamKing]

Hi, I'm wondering if someone can point me in the right direction with this question.

A material has a modulus of rigidity of 100 GNm-2 and a Young's Modulus of 250 GNm-2. Calculate the expected value of Poisson's Ratio for the material.

Poisson's Ratio is expressed as transverse strain / axial strain

So how am I supposed to work this out when the only information I am given is what's above? Or am I misunderstanding the question?

Any help would be appreciated

Thanks

Matt

For isotropic materials, there is a formula which relates E, G, and poisson's ratio. It's in just about every strength of materials text ever published.

For a quick refresher, look at this attachment:

http://www.colorado.edu/engineering/CAS/courses.d/Structures.d/IAST.Lect05.d/IAST.Lect05.pdf

Check out pp. 7 & 8.

 

[mattjones]

Thanks very much for that, I'll get reading!