You can export a mesh to a COMSOL Multiphysics file (.mphbin for a binary file format or
.mphtxt for a text file format), to a NASTRAN
® file (
.nas,
.bdf,
.nastran, or
.dat), or to a sectionwise text format.
To open the Export window for exporting meshes, from the
Mesh toolbar, click
Export (
), or right-click the
Mesh node and select
Export (
) from the menu.
Select a file type among the available formats in the File type list and enter a filename including the path in the
Filename field (or click
Browse to specify the filename).
Click Export to export a mesh to the specified file. A confirmation message appears in the
Messages window.
If you export a mesh to a COMSOL Multiphysics binary (*.mphbin) or text (*.mphtxt) file, you specify the type of elements to export using the Domain elements,
Boundary elements,
Edge elements (available in 3D), and
Vertex elements (available in 2D and 3D) check boxes under
Data to export. By selecting the
Geometric entity information check box, the export operation also writes information on the corresponding geometric entity index for each element to the file. Select the
Selections check box to also include selections that are defined on the current geometry in the mesh export. Such selections can then be included when importing a mesh. Select the
Export as second-order elements check box (2D and 3D only) to export the mesh including second-order elements. If you export a generated mesh that contains linear elements, the mesh to export is extended into a quadratic mesh with second-order elements.
If you export a 2D or 3D mesh to a NASTRAN file, you specify the type of elements to export using the Domain elements and
Boundary elements (available in 3D) check boxes. By selecting the
Geometric entity information check box, the export operation also writes information on each element’s corresponding geometric entity index to the corresponding property identification field of the resulting NASTRAN file.
Under Output settings, use the
Field format list to specify if the output NASTRAN file should be stored in the small field format (single precision), large field format (double precision), or free field format (comma separated). Select the
Export as linear elements check box to export the linear element information only. By default, second-order elements (serendipity elements) are exported if second-order elements are available. Second-order elements are available for meshes generated in COMSOL Multiphysics and for imported meshes already containing second-order elements.
When you select Sectionwise file (*.txt) from the
File type list, you can then select
Domain (the default),
Boundary, and
Edge (3D only) from the a
Geometry level list to determine the level of the exported mesh data.
When you export mesh to a sectionwise file from a Mesh node under a Component or from a
Mesh Part node where the
Use units check box is selected, the resulting file’s length unit will be determined from the length unit of the
Geometry node in the Component or the
Mesh Part node, respectively.
You can export a 3D mesh containing face elements to a 3MF file (3D Manufacturing Format file). From the Data to export list, select
Entire boundary as a single 3MF surface object (the default) to export the entire surface mesh as one 3MF object of Surface type, or select
Domains as separate 3MF model objects to export the surface mesh of each domain as a separate 3MF object of Model type and the remaining surface mesh, corresponding to the faces that are not adjacent to any domain, as a 3MF object of Surface type. Because the 3MF format only supports triangles, the export operation writes two triangles (defining a quad split) to the 3MF file for each quad element in the mesh. Second-order elements are converted to first-order elements.
