Autodesk Nastran 2019 Refuses to Process RBE3 Elements 1

[CDH007]

I'm having an issue where I've created a model in FEMAP with RBE3 elements and Autodesk gives me the following fatal error while processing the bulk data entries:

FATAL ERROR T2014: ENTRY REFERENCES AN UNDEFINED GRID 617601 IN FIELD 2
RBE3 617601 5002 123456 1. 123 518570 518625+X 1

That’s not a grid, that’s the element ID (even double checked the Autodesk RBE3 entry to verify).

I actually ran a small test model and got a slightly different version of the same error (this time it thinks the DOFs are a grid?):
FATAL ERROR T2014: ENTRY REFERENCES AN UNDEFINED GRID 123456 IN FIELD 5
RBE3 2713 191469 123456 1. 123 411165 411166+X 120

I exported the model both from FEMAP 2019.1 in NEI format and FEMAP 2020 in Autodesk format and Autodesk Nastran keeps picking up one of the RBE3’s as a fatal error.

Has anyone seen this before? Am I missing something simple? Is there an issue with the FEMAP bulk data translator? I normally use Simcenter Nastran but need to export certain data in NEI format.

Any help would be greatly appreciated!

 

[CDH007]

Okay, I was able to figure it out (in case someone else runs into this problem in the future).

A few of the RBE3 elements in the model had CTE or ALPHA values defined on them (they were converted over from RBE2s). Not technically correct for what I'm doing, but not an issue for NX/Simcenter Nastran.

Turns out NEI/AUTODESK Nastran does not allow for an ALPHA to be specified on an RBE3 (no block on the format list).