Deviations in modulus of elasticity / poisson's ratio

[DYV1973]

LS,

When applying a certain (stainless) steel, the modulus of elasticity, shear modulus and poisson's ratio can be found.
Can someone tell how accurate these figures are and what deviations can be expected. Are they e.g. within 5%? Should we have the materials tested every time to be accurate.

Thanks,
DYV

 

[CoryPad]

Elastic constants are relatively unaffected by the common things done by metallurgy. Using steel as an example, Young's Modulus usually is between 200 GPa and 210 GPa - a 5 % difference. The one common variable that does change elastic constants is preferred orientation (the result of heavy cold deformation), but the variations are usually around 10 %.




Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[metengr]

The above constants will be affected by service temperature.

 

[DYV1973]

Thank you for your replies.

The reason for my question: we do an optical measurement of strain of steel shafts (material is mainly C45E). This is an 0.5% accurate measurement, but when calculating back to forces the uncertainty is Youngs modulus (and for torsion also Poisson's ratio).

Can variations up to 10% be expected within 1 type of material? The heat treatment will always be identical (normalized), and afterwards only a few millimeters of material will be turned off.

Thanks,
DYV