Beginning with version 970 of LS-DYNA, a NASTRAN bulk data file can be read into LS-DYNA directly using the command:
*INCLUDE_NASTRAN nastran_input_filename 2,16,1
immediately following the *KEYWORD command in the input file. Although the NASTRAN model is NOT converted into a keyword input file, a structured input file (dyna.str) file IS created. The 2nd line following *INCLUDE_NASTRAN gives the beam, shell, and solid formulations to be used in the LS-DYNA analysis. If you encounter any apparent bug in this NASTRAN-to-LSDYNA translator, please provide LS-DYNA and NASTRAN input decks to bugs@lstc.com.
There is also a NASTRAN reader/translator of sorts in LS-Prepost. From the top menu bar, choose File > Open > Nastran File. If the model is successfully read, the model will appear and you can output it in LS-DYNA keyword format using File > Save Keyword.
We haven’t yet undertaken the next step which is to automatically convert DYTRAN data. Please provide a list of DYTRAN commands that you wish to be translated into LS-DYNA.