Importing Geometry into a 3D-CAD Model

Importing Geometry into 3D-CAD

Importing a geometry into the 3D-CAD module allows you to repair or modify it before running a simulation. Simcenter STAR-CCM+ allows you to import multiple CAD files at the same time, including multi-surface binary STL files (where multiple STL binary data is concatenated into a single STL binary file). You can also choose whether to import the geometry into an existing 3D-CAD model (if one exists in the simulation) or assign it to a new 3D-CAD model. You can also import CAD geometry directly to the geometry parts tree (see Importing Surface Data into Simcenter STAR-CCM+ ).

All imported bodies within 3D-CAD must fit inside a box with dimensions 1000 m x 1000 m x 1000 m, and a center [0, 0, 0] m, m, m. This means that a single body cannot be larger than 1000 m in any direction. Issues can occur in the downstream operations if the domain is close to this limit. For some features this limit is reduced to 500 m when other dimensions have already reached the maximum limit of 1000 m.

To import a CAD geometry into 3D-CAD:

1. Create a new Simcenter STAR-CCM+ simulation.
2. Launch the import action using one of the following options:
   • Select File > Import > Import CAD Model into 3D-CAD....
   • From the Mesh Generation toolbar, click (Import CAD Model into 3D-CAD....
   • If you want to import a geometry inside the 3D-CAD modeler, right-click on the 3D-CAD Model node at the top of the model tree and select Import > CAD Model. For more information on how to open the 3D-CAD modeler, see Creating a 3D-CAD Model.
     
     
     
     

     The 3D-CAD environment launches and a 3D-CAD model is created. Within 3D-CAD, an object tree that is specific to the 3D-CAD model is displayed. This tree contains Body Groups, Features, Design Filters, and Design Parameters nodes.

3. Select the CAD files to import.
4. Choose the import options. See 3D-CAD Import Options.
5. To begin the import process, click Open.

For multi-surface binary STL files, Simcenter STAR-CCM+ imports each surface as a sheet body. In 3D-CAD part surface names are imported automatically using the first word of the binary data headers as the surface name.

To import Creo .prt or .asm file containing metadata, it is recommended that you import the files directly into 3D-CAD using the Siemens Adapter for Creo instead of, first, exporting the geometry to a .step file.

The geometry is imported into the 3D-CAD model. If you import the geometry in parallel (Compute Processes greater than 1), bodies are tessellated asynchronously to optimize the processing time and improve visualization performance. The bodies are arranged in body groups according to the assembly structure from the native CAD package and are placed in the Body Groups manager node. The names of the bodies are also brought in to 3D-CAD.

You can change the way the bodies are organized in the 3D-CAD tree to appear as a flat list. See Controlling how Bodies are Organized in the 3D-CAD Tree.

The import process adds an ImportCad node to the 3D-CAD feature tree.

If any errors are encountered during the import, the operation completes with a Partially Successful status. For example, if a valid CAD file does not import bodies into 3D-CAD, the import operation is partially successful. A symbol appears next to the partially successful operation in the 3D-CAD feature tree.

To undo the import, delete the ImportCad feature.

Once the geometry is imported, you can modify it using the tools available in 3D-CAD.

Modifying Imported Geometry

3D-CAD Import Options

Select the appropriate import options for your CAD geometry.

Option	Description
Import Sheet Bodies	When activated, imports sheet bodies into 3D-CAD. Deactivate this option if you want to ignore sheet bodies and only import solid bodies.
Import Faceted Bodies	When activated, imports faceted data into 3D-CAD from tessellated file formats. If you are importing a CAD file format, the geometry is converted into faceted bodies and then imported into 3D-CAD as a faceted solid or faceted sheet. If there is any conversion error, the geometry is imported as a solid or sheets.
Import Metadata	When activated, imports the metadata associated with the bodies or body groups. Applies only to PLMXML, NX or JT Open files.
Check Body Validity	When activated, checks the validity of the CAD geometry during the import process. See Checking Geometry Validity.
Repair Invalid Bodies	When activated, attempts to repair invalid bodies during the import process. This option invokes both the Parasolid healing option from the CAD translator, and the automatic healing from the CAD Repair tool. Parasolid healing only takes place when you activate this option and import the CAD model into Simcenter STAR-CCM+. If you import the CAD model without activating this option, and subsequently run CAD repair manually, only the CAD repair healing is executed. See Repair Invalid Bodies.
Ignore Face Names	When activated, ignores the names of faces, edges, and vertices in the imported CAD geometry. Some CAD formats can contain unique names for every face, edge, and vertex. Large or complex CAD geometries can have a significant number of named faces, edges, and vertices. Importing such files into 3D-CAD can affect the performance of 3D-CAD. When deactivated, imports face names and colors. For CATIA, the face name and color is obtained from the parent feature of the face and not the face itself.
Ignore Unnamed Face Colors	When activated, ignores the unnamed face colors in the imported CAD geometry. When deactivated, imports the unnamed face colors, while following Simcenter STAR-CCM+ internal naming convention.
Simplify Assembly Structure	Attempts to match the assembly structure with the file in the native CAD package.
Split Periodic Faces	When activated, splits the periodic faces in the imported CAD geometry. For example, periodic faces such as cylindrical faces are split into two semi-cylindrical faces.
Create New 3D-CAD Model	When activated, allows you to create a new 3D-CAD model. This option appears as read-only if you are working inside a 3D-CAD modeler session. 注 This option is not available when you use the Import > CAD Model option inside the 3D-CAD modeler.
CAD Model	Allows you to import a geometry into an existing 3D-CAD model. This option appears as read-only if you are working inside a 3D-CAD modeler session. 注 This option is not available when you use the Import > CAD Model option inside the 3D-CAD modeler.
Importer	Siemens Adapter supports CATIA V5, CATIA V4, CATIA V6/3DExperience, CGR, NX, Solid Edge (Windows only), JT, SolidWorks, Inventor, Creo, STEP, IGES, ACIS, and IFC import. For CATIA and STEP files. No additional CAD Exchange Reader licenses are required for the NX, Solid Edge, IGES, STEP, or JT Adapters. All other adapters require the CAD Simcenter STAR-CCM+ Exchange license. When using Siemens NX Adapter import option, Simcenter STAR-CCM+ imports multi-bodied NX CAD parts as leaf composite body groups.