interference betwen surfaces in a pretensioned bolt connection 1

[n3l3]

Hi all!
im modelling a bolted prestressed connection as showed in the image attached, is a 3d element model, and what u see is a section cut, in order to see the hole.
Im pretensioning the bolt with a temperature step, applied to the beam element section.(bolt central body)
the problem is that i get an interference between the bolt head and the compressed piece.
I know the problem is not in the temperature step because if I make a coupling betwen the beam element end (1) with the hole edge (6) it works nice.

*the interaction is surface to surface explicit

*the interaction property has normal behaviour with "hard contact", and tangential behaviour with "rough".

*the interaction property its the same than in the contact between compressed pieces (3), and there is working.

Has anybody an idea?

Thanks and sorry because of the language mistakes.

 

[corus]

It looks like it's just a mesh incompatibility problem, exaggerated by your scaling. You could try reversing the master/slave surfaces or, as the bolt head appears to contact at all points, just tie the two surfaces together. I'd also change your element type to C3D8 as the C3D8R element (or the opposite way round) seeems to be hour-glassing in the bolt head.



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[n3l3]

thanks a lot for your reply, Im going to try this right now.

best regards

 

[n3l3]

changing C3D8R to C3D8R solved the interference problem.
now the model does not behave like expected but thats another problem so i´ll close the thread.
thanks a lot Corus.

 

[n3l3]

C3D8R to C3D8
= )

 

[corus]

Generally I'd never use the C3D8R element as even though it's supposed to be 'cheaper' and in the manual says it prevents hour glassing, it does exactly the opposite, and gives rubbish results.

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