Learning Forum

[nmar]

Hello dear simulation-friends

On a current project I ran into a problem with modelling of temperature-dependent material properties.

What I want to do:

• Static-structural simulation of a axisymmetic part
• The part is subjected to a given temperature field (also axisymmetric, considered as steady-state)
• The temperature dependency of the mechanical properties are NOT negligible

To get the temperature-dependent properties the temp-field is imported with a "external data" block from a .csv file. The data is available as a 2D field, which are then projected around the axis using a cylindrical coordinate system in mechanical. From the visual feedback this step seems to work.

The problem:

When I run a simulation on this part I always get an anisotropic deformation. This even happens, when my structural load (in this case rotational velocity) of negligible magnitude are.

[nmar]

Sorry, forgot to add: I am using Ansys Workbench 2021 R1.

[John Doyle]

You have a temperature body load that varies about the axis of the cylinder. Is that what you are trying to simulate? If so, why would you expect the thermal differential expansion result to be axisymmetric? It seems like it is correct.

[nmar]

Thanks for the answer jjdoyle!

No, the temperature should vary along the axis of the cylinder and (though just a bit) in radial direction but be axisymmetric. This is also what I get as visual feedback from my import:

What I found out in the meantime: if I orient everything such that the axis of the cylinder aligns with the global x-axis I get what I expect. Why does this happen?

Another interesting behaviour: when the thermal expansion coefficients are set to zero, I still get a deformation from the temperature field. Why is that?


Best regards
Mario