Poisson effect with thermal expansion?

[GeorgeEllwood]

Hello,
I'm trying to model a component with anisotropic thermal expansion. When I change the temperature and solve the model, the results don't match up with what I'm expecting. I was wondering if this might be due to a poisson effect of the material? i.e. the material has the largest thermal expansion in the x direction, when heated this causes the x the direction to increase a certain amount, in ANSYS would it also result in the y & z directions contracting? This seems to be what my model does even though I think it shouldn't.
I don't want to remove the poisson's ratio from the material because there are structural effects that will require it to be there.
Any help or advice would be greatly appreciated.
Thanks
George

 

[flash3780]

Thermal expansion is isotropic in most engineering materials. If you're looking at pure thermal expansion, say a block of steel floating in space, it will expand equally in all directions. What is it that you're modeling? Do you have a picture? What do your hand calculations look like?