Orthotropic material

[maartenbrink]

Can anyone clarify the conventional equivalent to the suggested form of orthotropic properties in NX5.0 Nastran?

This question is asked before by potrero (

http://www.eng-tips.com/viewthread.cfm?qid=223824&page=128),

who suggested the following interpretation;

Poissons_Ratio_X = XY
Poissons_Ratio_Y = YZ
Poissons_Ratio_Z = ZX
Shear_Modulus_X = XY
Shear_Modulus_Y = YZ
Shear_Modulus_Z = ZX

However, on the following URL another interpretation is given;

http://iberisa.com/soporte/femap/composites/nafems_benchmark_composite_test_r0031_3.htm

Poissons_Ratio_X = XY
Poissons_Ratio_Y = XZ
Poissons_Ratio_Z = YZ
Shear_Modulus_X = XY
Shear_Modulus_Y = XZ
Shear_Modulus_Z = YZ

Which is correct?

Regards