Assigning Poisson's Ratio

[Hemanth_T_N]

Hello All..!,


I am new to Textile composite modeling as well as Texgen. I have a query with regard to specifying the Poisson's ratio of yarns.

Usually all the textbooks of composite materials have two subscripts for Poisson's ratio. For example, Nu12 would mean the Poisson ratio in the 2-direction due to load being applied in the 1-direction. And for orthotropic material which I am working on, I understand that Nu12 is not same as Nu21. However Texgen software only has one subscript while specifying the yarn properties under Modeller>>Assign Yarn Properties.

So I am just curious to know which value should I provide for Poisson's ratio.

I would be grateful for any clarification/help/Advice on this problem.

Have a Nice Time..!

-Hemanth T N

[louisepb]

Hi Hemanth,

The assumption in TexGen, for the purposes of export to Abaqus is that the material is orthotropic and therefore there is a specific relationship between Nu12 and Nu21 which is built into Abaqus, requiring only one as input. The Nu x, y and z in TexGen are output as the 3 Poisson's ratios in the orthotropic elastic material type which is exported to Abaqus. They might be clearer if called Poisson's ratio XY, XZ and YZ.

Hope that helps,
Louise

[seansquares]

Could you clarify the ordering of the Poisson ratios here? I just want to make sure that I am interpreting them correctly.

Do you mean that:
Nu x = Nu XY = -strainX / strainY
Nu y = Nu XZ = -strainX / strainZ
Nu z = Nu YZ = -strainY / strainZ


Thanks,
Sean Skweres

[louisepb]

Hi Sean,

Yes, that's correct.

Best wishes,
Louise