Showing results for 
Search instead for 
Did you mean: 

Reading example NASTRAN models from User's Guide




I'm attempting to read NASTRAN models from the NX manuals into FEMAP, and all model components are being skipped during the read.


For a simple example, Listing 3-1 "Truss Example Input File," I have attached below (the .txt extension is required by this forum).  This is a simple truss with 4 nodes and 5 rods.


I have attempted to read using two approaches:

  1. "Open" -> select filetype "Nastran (*.dat, *.nas, *.bdf, *.blk)" -> open .DAT file
  2. "New" -> "File" -> "Import" -> "Analysis Model..." -> "NASTRAN" -> "NX Nastran"

The resulting messages are



Import Model
Opening File C:\nastran\TRUSS1.DAT...
Skipping GRID 1 0. 0. 0. 3456
Skipping GRID 2 0. 120. 0. 3456
Skipping GRID 3 600. 120. 0. 3456
Skipping GRID 4 600. 0. 0. 3456
Skipping CROD 1 21 2 3
Skipping CROD 2 21 2 4
Skipping CROD 3 21 1 3
Skipping CROD 4 21 1 4
Skipping CROD 5 21 3 4
Skipping PROD 21 22 4. 1.27
Skipping MAT1 22 30.E6 .3
Skipping FORCE 10 4 1000. 0. -1. 0.
Skipping SPC1 11 123456 1 2
0 Coordinate System(s) Translated.
0 Node(s) Translated.
0 Property(s) Translated.
0 Material(s) Translated.
0 Element(s) Translated.
0 Load Set(s) Translated.
0 Constraint Set(s) Translated.
0 Connector(s) Translated.
0 Connection Property(s) Translated.
Beginning Update of Database...
Database Update Completed. No Errors.



I assume there is a simple oversight on my part, but the .DAT file seems to include the required keywords, "CEND", "BEGIN BULK", "ENDDATA", and data.  Why are all the model parts being skipped?


Thanks in advance,

Sam Range


Re: Reading example NASTRAN models from User's Guide

Siemens Phenom Siemens Phenom
Siemens Phenom

The problem is that originally the files you have had tab characters to move the various data into the normal Nastran 8-character, fixed format fields.  At some point those tabs were improperly converted to spaces and now the data is in the wrong columns to be a valid Nastran file. I believe you will find that they won't run in Nastran either.

Re: Reading example NASTRAN models from User's Guide


That absolutely seems to be the case.  For the benefit of future googlers, an amended .DAT with the bulk data section reformatted.