How can I simulate bolt pretension

[somebodyfromworld]

How can I simulate bolt pretension in this connection. Yellow and Green parts are tightened with 120Nm at the same time yellow part is pushing grey part towards green making a sealing connection in between. When the connection is tight I have to apply internal pressure to check that the sealing between grey and green parts is still intact and threads are strong enough. Any ideas would be appreciated. 2D axisymmetric analysis.

 

[SSCon]

You could apply a thermal load to the grey part as the first load step. Increase the temperature until you get the desired force reaction on the sealing surface. Would need to make sure you've enough clearances to ensure the temperature change doesn't cause any unintended mechanical loads.

 

[somebodyfromworld]

Thanks for the answer, Do i need to set any special material property to the model so it expends due to temperature because now it is only about 200C the max and after that it is no changes in results.
Here is what i have for the material
[ul]
[li]Isotropic Elasticity[/li]
[li]Multilinear Isotropic Hardening[/li]
[li]Tensile Yield Strength[/li]
[li]Tensile Ultimate Strength[/li]
[/ul]

 

[shiraz883]

You need to include "coefficient of thermal expansion" in the material properties of the parts to take the effect of temperature induced expansion.

Shiraz
Sr. Engineer

 

[somebodyfromworld]

thanks