creating bolt pretension load

[Tinni1]

Hello,

I am trying to create the bolt pretension load in the Abaqus explicit solver.
Since, the bolt load, that is available in the static general solver is not available in the explicit solver, I am trying to create the bolt pretension using a temperature gradient(Based on guidance provided in the literature)to create an equivalent amount of loading, as that in pretension.
My questions are below:

To apply the temperature load, I need a surface, which I presume should be the inner circular surface of the bolt shank at the mid-length of the bolt, as I have seen in the bolt load case in a static general solver. In the part module, I have defined this surface. But while applying the temperature load, I am not able to select this inner surface. I am only able to select the outer perimeter of this surface.

Could anyone please advise how I apply this temperature gradient on the bolt? Should it be on the inner circular surface at the bolt shank mid-length or on the outer periphery of this surface, or on the entire outer surface of the bolt shank?
If it is on the inner circular surface at the bolt shank mid-length, how do I select this surface on the load module in Abaqus?

Many thanks!

 

[FEA way]

You can simulate pre-tension in Abaqus/Standard and then use the import technique to continue the analysis in Abaqus/Explicit.

The approach with the thermal expansion is usually used for beam representations and the temperature change should be applied to the whole bolt. An orthotropic material model might be needed.

 

[Tinni1]

Thanks for your response.

Could you please provide some guidance on how to use the import technique to continue the analysis from Abaqus standard to Abaqus explicit? Is there any reference around this?

I am aware that for bolt pretension, I need to create a separate step for bolt pretension. Following this how I should use the import technique?

Regarding the temperature load, as you say it should be applied to the whole bolt, does that mean the whole bolt's outer surface? Why an orthotropic material model might be needed?

Thank you!

 

[FEA way]

Check the documentation chapter "Transferring Results between Abaqus/Explicit and Abaqus/Standard". The procedure varies depending on whether you are using Abaqus/CAE or keywords. You just have to import the deformed shape and state of the material after applying preload.

I mean applying it to the whole volume of the bolt. Orthotropic material is used to ensure thermal expansion only in the axial direction.

 

[Tinni1]

Thank you so much!

 

[Abishek0708]

Hi Tinni1,

I am also trying to apply preload to the bolts using the temperature field. How did you manage to achieve the pretension after all?

Regards,
Abishek