Trelis 16.4 User Documentation
To import a mesh from an Nastran format file
Import Nastran [Mesh Geometry] '<input_filename>' [Feature Angle <angle>] [Nobcs]
Including the keyword Mesh Geometry will instruct Trelis to create mesh-based geometry. This will provide the user with the ability to remesh geometric entities. If the user does not import with the Mesh Geometry flag, he will have to tell Trelis to draw the mesh after the import is done in order to view it.
The Feature Angle is used when building the surface topology to determine when to split a surface into two surfaces. If the angle between two neighboring element normals is less than Feature Angle, then the two elements will be placed on separate surfaces. If the keyword Feature Angle is not supplied, the default 135 degrees is used. For a description of importing mesh geometry see Importing Exodus II Files.The keyword nobcs can be included if boundary conditions are not to be imported.
It should be noted that Trelis sometimes cannot successfully generate
mesh-based geometry for complex models. If this occurs, import
the mesh without the Mesh Geometry flag, and draw the mesh to view it.
See http://en.wikipedia.org/wiki/Nastran for more information on the NASTRAN file format.