Hello,
I am doing deflection analysis of a pipe using GRE (Glass reinforced epoxy) pipe for which i ahve the following properties @ 21 Deg. C from material supplier

Hoop Tensile modulus = 23250 MPa
Poisson's ratio axial/hoop = 0.93
Axial Tensile Modulus = 10000 MPa
Poisson's ratio hoop/axial = 0.40

In FEA when i enter the poisson's ratios i get a message that the values ae not practical or with these values strain energy will be negative. I am using transvere isotropic format for GRE in FEA.

Will you suggest me on how to correct the problem of poissonss ratio.

Not sure if i have read your post correctly, but i wouldnt use an isotropic material for your composite.
Where did you determine your youngs modulus from, it seems high?

I got the young's modulus from supplier. I am using transverse isotropic i.e E2=E3 (hoop plane).

ANSYS is showing an error in poisson's ratio. I was thinking that poisson's ratio of 0.93 is not correct. but i am not sure.

Please suggest.

Arline

Did i say youngs modulus?? I meant to say Mr Poisson's was very high (0.93)

when the poisson ratio approaches 0.5 most results are expected to explode.  incompressible materials (those maintaining volum under load) have values of about 0.49

check for more appropriate values

Hoop Tensile modulus = 25200 MPa
Poisson's ratio axial/hoop = 0.65
Axial Tensile Modulus = 12500 MPa
Poisson's ratio hoop/axial = 0.40

Above are the revised properties after speaking material supplier.
Can somebody help in understanding the "Poisson's Ratio AXIAL/HOOP". I typically always seen as just poisson's ratio but why they are saying that Axial/hoop and Hoop/Axial.

Assume the pipe axis in Z-direction, then what will be PR(Poisson's ratio ) in XY, YZ & ZX directions from above given values.

Which formula i need to use to calculate shear modulus for transverse isotropic materials.

Please help me in my learnings about composite.