Thin Body Cone: Buckling Analysis due to Vacuum

[Anonymous]

Hey guys,

I'm having trouble performing a modal linear buckling analysis on a thin body cone. I've set up a pressure load and constrained the edge of the cone. 

I'm getting the error E5004 and I've tried the suggested workarounds (http://help.autodesk.com/view/NSTRN/2017/ENU/?guid=GUID-0B6EAC2C-29C2-4AEF-B3FC-91325EE92CD7).

I've attached an image of the setup and the part in question. 

I suspect I've set up something wrong with the thin body itself? Any help or solutions would be greatly appreciated!

Thanks,

Kelvin

[shigeaki.k]

Hello @Anonymous ,

could you tell us which version of Nastran In-CAD you are using? I am using 2018.2.1.428 and I had no issue running the analysis. 

Regards,

Shigeaki K.

[shigeaki.k]

Hello @Anonymous ,

if you are using a older version where two subcases appear then the below article might help.

Error: "FATAL ERROR E5004: STIFFNESS MATRIX SINGULAR OR NON-POSITIVE DEFINITE " when performing a buckling analysis in Nastran In-CAD

Regards,

Shigeaki K.

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