Meshing problem of circular steel tank

[TSOFA]

The structure is the same that I had seismic load generation problems at the topic "Circular Tank: seismic load generation". I added the steel panel at the roof as shells but I can not get the mesh to be right. Why is that? I tried to run the analysis with the wrong mesh and of course the results were not reasonable ( non uniform deformation under uniform static loading of a symetrical structure).

[Rafal.Gaweda]

My meshing:

[TSOFA]

This looks better, but I don't know if it's acceptable. I will run the analysis to see if the results are reasonable this time and I let you know, thanks

[Artur.Kosakowski]

You may also consider creating an arch (polyline) and revolving it with number of divisions matching the meshing of the wall.

[TSOFA]

I want the steel panel roof to match the geometry of the supporting structures (bars). In order to model this supporting structure, I didn't use an arch for the geometry of the main bars (I don't know if it's possible to create a steel bar from an arch). What I did is that I used crooked lines that were forming a very similar geometry. Don't you think that if I use the arch for the panel it will not be assembled properly with the bars?

[Artur.Kosakowski]

You may use the polyline following the nodes of the steel beams instead of the arch (that's why I used the word polyline in my first answer )

If you find your post answered press the Accept as Solution button please. This will help other users to find solutions much faster. Thank you.

[Rafal.Gaweda]

 (I don't know if it's possible to create a steel bar from an arch). 

Possible.

[TSOFA]

I followed your advices of how to mesh the shells and how to create the roof plate ( polyline). Even Though the mesh looks really nice, I still have warnings and when I run the analysis the deformations are not reasonable (I will run it again and send a screen print). The warning of duplicate load cages I assume that is due to the fact I used the same combinations as ULS and SLS.

[Rafal.Gaweda]

1. Do not ever use Kinematic links - turn them off in job preferences

2 walls should be meshed with divisons 1x1 to get coherent mesh with roof.

Corrected file attached

[TSOFA]

Thank for the file. At your model DSC algorithm is turned off, should I turn it on or leave it like this? When I turn it on, I have instability type 3 (is this a huge problem?) again.

[Rafal.Gaweda]

leave it as it is

[TSOFA]

This are my results without having DSC algorithm active. Something is wrong. Do you have the same resutls?