Calculating Poisson's Ratio with a Modulus of Rigidity & Young's Modulus

AI Thread Summary
To calculate Poisson's Ratio for a material with a modulus of rigidity of 100 GNm-2 and a Young's Modulus of 250 GNm-2, a formula relating these values is necessary. The discussion highlights that this relationship is commonly found in strength of materials textbooks. A user suggests referring to a specific attachment for further clarification on the topic. The inquiry revolves around understanding how to derive Poisson's Ratio from the provided moduli. The conversation emphasizes the importance of established formulas in material science for such calculations.
mattjones
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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
 
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mattjones said:
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.
 
Thanks very much for that, I'll get reading!
 
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