Error of membrane stiffness matrix D?

[jb.quocan841038]

I think RSA has mistake between value f12 and f22. Could anyone help me?

[pawel.pulak]

Why do you think so?
If you select "Orthotropic" tab in "New Thickness" dialogue, then select "material orthotropy", select the same values of stiffness reduction coefficients for perpendicular directions n1, n2 and click "Display: you will see that f11=f22>f12 (Dxxxx=Dyyyy>Dxxyy according to help of Robot) which are reasonable relations.
Don't you check these values for strongly non-uniform orthotropy, where relations like f11>f12 >f22 are possible?

Regards,