Open Autodesk Simulation Mechanical Models

Autodesk Simulation Mechanical uses *.fem files to save FEA models.

The format of the .fem file changed at version 20. If you use the .fem file option to open a model earlier than version 20, it is treated the same as opening a legacy model. See the following for more information.

Open models

1. Click Open.
2. Set the Files of type to Autodesk Simulation FEA Model (*.fem).
3. Browse to the appropriate file and click Open.

You can also drag a file into an open Autodesk Simulation window.

Note: Set the Files of type to Autodesk Simulation Archive (*.ach) to retrieve an archive. Simulation Mechanical decompresses the archive and opens the model. For more information, see Archives.

Open legacy models

Files prior to version 20, store the Autodesk Simulation model in *.dmit files (copy of CAD parts), *.esx and *.fem files (the mesh), and *.esd files (Superdraw III mesh). Opening any of these file types converts the old model to the new format. We recommend that you back up your archive as the conversion is not reversible.

Files prior to release 12 store the Autodesk Simulation model in a file without an extension (the dot nothing file). You can import these models using the standalone program DotNothing2FEM.exe that we provide in the Autodesk Simulation Mechanical installation folder. Open these old models as follows:

1. Double-click DotNothing2FEM.exe in the Autodesk Simulation installation folder.
2. In the Legacy Model Updater dialog box, click the button for the Legacy filename. Browse to your file and click Open.
3. The new model name displays in the FEM filename field. Keep the name or enter a new name.
4. Click Update to begin the conversion process. The status area indicates various stages in the conversion process.
5. During the conversion, review the converter log file, click Done, and select a unit system. (Prior to release 12, models did not use a unit system.)
6. The status area of the Legacy Model Updater dialog box is blank when the conversion is complete.
7. Use Autodesk Simulation Mechanical to open the .fem file.

Attention: The conversion process does not read the following items from the original model. Inspect the model and enter the appropriate data

• Element normal coordinate of plate-like elements (entered in the Element Definition). The coordinate controls things such as the direction of pressure loads, temperature gradient through the thickness, and stacking sequence of composite element laminae.
• The gravity direction multipliers (entered in the Analysis Parameters). The old releases stored this data in a fashion that is not compatible with the current software.