If you are constantly having to work with large models and larger output in XDB format, MSC Nastran has come out with a good solution. A common fatal message encoutered while writting out large size xdb files is UFM 6062(DBC). There are standard solutions available to avoid this fatal message. However, by including the following in NASTRAN SYSTEM CELL and FMS, I have been able to run models and output upto 40GB of xdb file:
- Insert in NASTRAN SYSTEM CELL - NASTRAN DBCFACT=4
- Insert in FMS - ASSIGN DBC='filename.xdb',RECL=32768,UNIT=40,DELETE
NASTRAN DBCFACT=4 is a new command introduced from MSC Nastran 2005 + versions. This command creates a new format of xdb file and supports the creation of virtually unlimited size of xdb.
Example Input:
$ Direct Text Input for Nastran System Cell Section
NASTRAN SYSTEM(151)=1
NASTRAN BUFFSIZE=65537
NASTRAN DBCFACT=4
$ Direct Text Input for File Management Section
ASSIGN DBC='nl_150bar.xdb',RECL=32768,UNIT=40,DELETE
$ Nonlinear Static Analysis, Database
SOL 106
$ Direct Text Input for Executive Control
CEND
Example Input:
$ Direct Text Input for Nastran System Cell Section
NASTRAN SYSTEM(151)=1
NASTRAN BUFFSIZE=65537
NASTRAN DBCFACT=4
$ Direct Text Input for File Management Section
ASSIGN DBC='nl_150bar.xdb',RECL=32768,UNIT=40,DELETE
$ Nonlinear Static Analysis, Database
SOL 106
$ Direct Text Input for Executive Control
CEND
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