Learning Forum

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Hello,

I have meshing problems of the attached model in AIM (see attached images): 

More precisely AIM has problems recognizing the shared topology between shell and beam members. It is strange, because visually I cannot see flaw, but there are no meshes created for the beams and AIM sends Warning/Error messages – see printscreen attached.

The error message suggests to ’…select the modeling option and use shared topology…’

Shared topology is properly defined in SCDM, please check attached SCDM model.

Please help me to solve this issue.

Regards,

Csaba

[Naresh Patre]

Hi steelxpert

I am looking into this issue and will get back to you with my findings.

[Naresh Patre]

Hello steelxpert

There were some duplicate bodies which were resulting in mesh failure. If you go to Repair toolbar and click "Duplicates" feature, it will highlight 3 regions as shown below:

 

Fixing these regions help to generate a successful mesh.

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Hello Naresh Patre

Thank you for the tip, this way the mesh creation was succesfull.

So I went further and defined simple structural physics that involve rigid supports and inertial load only.

I defined manual contacts between the lower case duct legs and the supporting beam - see the attached models again:

When solving the physics I got (4) error messages - see attached screens.

Please help me how to fix the solving issue(s).

[Naresh Patre]

Hello steelxpert

I will look at the model and get back to you.

[Naresh Patre]

Hello steelxpert

I checked the transcript file and it had reported following error:

A large negative pivot value has been encountered in the global assembled matrix ...

Typically this error is the equivalent of 'rigid body motion' for structural (insufficient boundary conditions leading to the geometry 'flying' away). 

I reviewed the model and noticed that contacts need to be defined for the bodies located around the cylindrical body. Below image shows one show location of bodies. Can you review these locations and any other locations and define appropriate contacts and try solving the model again?

 

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Hi Naresh Patre

Yes, thank you, I made a mistake. I defined the missing contacts and worked fine.

Last question: can you comment why the 'Interface generator' cannot find any contact, doesn't matter how big the 'Pinball Radius' is (so I ended up manually define the contacts)?

Regards,

Csaba

[Naresh Patre]

Hello steelxpert

Glad to know that the issue was with missing contacts.

Regarding contact detection, tt appears to be some conflict with Share Topology. If I delete the share topology and import the model, the contacts are detected by the interface generator. I will report this issue to the development team.

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hello Naresh Patre

Thank you in advance.

[Naresh Patre]

Hello steelxpert

The interface generator issue observed in this problem has been fixed in upcoming 2020R2 build. The interface generator created contacts between faces that were missing earlier. See below snapshot.

 

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Hello Naresh Patre

Thank you for the update