Loads being applied at origin of part automatically causing fatal error

[Anonymous]

I am having a Problem with Nastran IN CAD.

When I try and apply a pressure load on a surface, the load is also being applied at the origin of the part and this is causing the Nastran Solver to give me FATAL ERROR: T2038 .

Since the origin is just a point and has negligible mesh size, any load applied on it will cause massive stress and displacements. I am assuming this is the reason the error is occurring.

Please see the above screencast to get an idea of the problem.

[John_Holtz]

Hi @Anonymous

Sorry for the delay in replying. Hopefully this will be the solution (or at least lead to a solution) to your problem.

According to this article, the T2038 error is related to contact defined in the model. I think it is not related to the applied load. If you delete the load that appears at the origin, does the analysis still gives the T2038 error? (I think the load is a convenient way to "see" that there are 0 size elements at the origin, but I could be wrong.) Error: "Fatal Error T2038" after using automatic surface contact generation in Nastran In-CAD

If the problem is with the contact and the article is correct, the contact is defined using some geometry (a face, an edge) that does not have any elements. The key will be to find which geometry is causing the problem and removing that from the contact definition.

Feel free to attach your model if you are still having problems with it.

P.S. I am going to edit the article to make some improvements to the description. The edited article will be available in a few hours.

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[Anonymous]

@John_HoltzThank you for replying.  You said

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 If you delete the load that appears at the origin, does the analysis still gives the T2038 error? (I think the load is a convenient way to "see" that there are 0 size elements at the origin, but I could be wrong.)

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However, I didn't find any way to delete the load at the origin. When I apply the load on the surface, it automatically applies that load at the origin. I don't have access to the File right now. I will post it here within 48 hours. I remember trying to troubleshoot the model for a long while. I thought maybe there is a sliver or a point in space or some sort of geometry and I did all sorts of things to try and select/delete/supress that to no avail.

As for the contacts, I had manually applied the contacts too but the problem persisted. I had to format my system due to a small accident and no longer have access to Nastran. I am waiting on some components to get repaired and then I'll have to reinstall all my softwares, so I can't even try out your solutions right now.

I do however have access to backups of the file which I will be sharing with you(within 48 hours). Please try and find the issue.

Thanks for the Help 🙂

[Anonymous]

@John_HoltzI have attached the files. Please take a look.

[g.ceruti]

Hi @Anonymous,
I had a quick look to your model:

• the outer curved shell surface is meshed with 2D shell elements on all its boundary surfaces, not a singol 2D element layer. Is that your intention? ( however this does not matter with your fatal error)
• if you enable the nodes display option, you can see that there are no nodes in the origin
  furthermore if you have a look at nastran file (*.nas) you can't find any GRID card of any node placed at origin

So, I think that the load arrows at the origin are only a load glypho display error

[Anonymous]

@g.cerutiYes, I did mesh it as shell elements since trying to mesh it as a 3D object was constantly throwing up errors. If it is only a glyph error, why the fatal error??

Any advice would be of great help. Thank you.