Solid to solid interaction not working

[matcunni]

Dear colleagues,
I'm having a little problem here concerning contact between two solids.

I've modeled each part separately and then assembled them, I've defined and assigned boundary conditions, materials, meshes, constraints interactions, loads.
I've submitted the job, and everything seems to work except one interaction.
When I increase the scale factor for the deformed shape, one solid penetrates the other. I think this is not a graphical issue because when I plot CPRESS, it's non-zero in all the other contact places excepting this one.

Things I've tried:

General Contact - Without modifications. All the interactions worked except the troublesome one
General Contact - Plus Surface to surface contact in the problem region - Slave surface with finer mesh than Master. - Same result
General Contact excluding the three surface with the problem, and defining manually Surface to surface contact on them - Same result
Same as above, adding Automatic surface smoothing in the manually defined contact region - Same result.
I don't think defining every interaction manually would help here.

This is an image of the undeformed model

Here's the deformed shape

Another view. CPRESS is zero in the vertical Pipe.

The two collinear pipes are compressed, The difference in compression is 45tons. I think the vertical plate welded to the vertical pipe should press against the last one.
The "weld" is modeled geometrically and tied to the vertical pipe.

I'm out of ideas here.

Any help or comment would be very much appreciated

 

[Mustaine3]

Mhh, the general contact should have found it, except you also have a tie constraint defined there.

'hard to say without seeing the definition in the model.

 

[matcunni]

Attached is the input file.
This thing is out of curiosity, it's not the first time that this has happened to me.

I know there's a tie constraint there, but the vertical pipe is partitioned in coincidence with the weld, and the tie is in that region. The Surface to surface - "Hard" interaction is defined in the surface adjacent to this "weld partition".

 

[Mustaine3]

The contact is working fine.

You should think about the effect that the deformation scale factor has on the result visulization.

 

[matcunni]

Thanks for the input Mustaine.

But why is CPRESS=0 everywhere there?. I thought on the deformation scale factor. But in every other contact region I've CPRESS not equal to 0, and when I increase the deformation scale a bit, I don't see interference anywhere but there.

As I'm writing this I'm realizing that I could have supressed the compression forces in the horizontal bars, put some pinned constraints there and increase the compression in the perpendicular bar. That way I could easily test the interaction. Will try that on monday and post results.

Cheers

 

[rrg1016]

Another thing that you can do is to analyze COPEN... If the variable CPRESS=0, COPEN should be >0 (Not in contact yet). If this statment is false, there is something strange!