Learning Forum

[mital.patel]

I am performing a piping analysis in ANSYS Workbench using transient thermal and static structural analyses. The setup is as follows:

1. Pipe Geometry: Length = 2450 mm, Material = SS304L (α=17.5×10−6 K−1).
2. Temperature: Reference temperature = 313 K, Cryogenic temperature = 90 K.

The hand calculation for thermal contraction using $\cdot L$ gives −9.56 mm. However, the deformation result in ANSYS differs.

Questions:

1. Should the deformation in ANSYS match the hand calculation? ansys showing 8.78mm why ?
2. How do I ensure the reference temperature is correctly applied in the analysis?
3. Are there other factors in ANSYS (e.g., boundary conditions or gradients) that might affect the result?

[peteroznewman]

1. The deformation in ANSYS will match the hand calculation if you have a stress-free boundary condition holding the pipe, have a uniform temperature in the pipe and have correctly assigned the reference temperature and temperature load.
2. The reference temperature is set in Engineering Data as a Material Field Variable and in the Isotropic Secant CTE.  The reference temperature is also in Static Structural under Environment Temperature. Make sure all temperature entries use the same temperature.
3. The hand calculation won’t match if you use a boundary condition that prevents the free thermal expansion of the material or if the material does not have the same uniform temperature applied.

You say you used a transient thermal, why? There is no need to use any thermal analysis to match the hand calculation. Use a Static Structural model and apply a Thermal Condition under the Loads category on the Environment tab.