SPLIT Compound for Pre-Tension Load (bolted joint)?

General Questions
1

Is there a workflow that allows application of a Pre-Tension load to a 2-part fastener head/shank that has been meshed as a SPLIT compound? (The bolted joint tutorial on YouTube, which showed non-split compounding, was very helpful for getting me started with PrePoMax!)

Background:
:diamonds: I am modeling a bolted joint with an external tensile load applied, so it is important that the abutment surface treatment allows for the possibility of joint separation (e.g. frictional contact, so SPLIT compound is ideal here)
:diamonds: Compounding is also useful in that it imprints the mating surfaces, e.g. the bolt head bearing surface imprinted on the joint plates, for setting up contacts, and of course creates conformal nodes.
:diamonds: But, the split compounding between the bolt head/shank prevents the Pre-Tension load from working as intended since the code doesn’t recognize the two components as being of the single body.

I’ve tried putting individual Pre-Tension loads on each side of the fastener, but the deformation and stress results are not correct.
I also tried combining the head/shank meshed parts, but had similar results.

The best alternative I’ve found so far, it to generate a SPLIT compound mesh on the entire assembly to imprint all key mating surfaces, then create a new ‘sub-compound’ of the fastener that is NOT-SPLIT.
The remaining difficult part is that the mesh between the non-split fastener compound and split joint compound is still non-conformal, and I’ve struggled with convergence and ≈100x longer run times this way.

I’m impressed with the great work on PrePoMax, the GUI is very well thought out and easy to use; I actually like the workflow better than some of the commercial codes out there :slight_smile:

Regards,
Brandon

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1 Like
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I think I understand the problem. At the moment, there is no possibility of performing what you need. So we would need a feature to select which parts to split (more difficult to add) or a feature to combine parts together again - merge coincident nodes (much easier to add).

1 Like
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Understood, Matej. Thank you for the feedback!

4

An additional benefit of the “merge coincident nodes (much easier to add)” idea; this option would also potentially work on imported meshes, too, I would think?

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Exactly. And then, some features to change or edit the mesh manually would also be beneficial.