Inserting Finite Element Model Representations

You can insert new finite element model representations in an existing product.

Before you begin: The product must be open; for example, in the Assembly Design app.
See Also
About Finite Element Model Representations
  1. From the Compass, click Simulation Apps and select the Structural Model Creation app.

    Each time you enter a model creation app, a new finite element model representation is created.

    The Create Finite Element Model dialog box appears.
    Important: The options available in the Create Finite Element Model dialog box vary depending on whether the product contains one or several 3D solids, as well as 2D surfaces.
  2. Choose which geometries will be initialized as supports of the mesh:
    OptionDescription
    Main body in each shape Initializes the main body only (that is, the PartBody). If the PartBody is empty, the app initializes another solid body. If all solid bodies are empty, the app initializes any ordered geometric set until there is a single 3D result.
    All geometries in all shapes Initializes all geometries of the part or assembly.
    Select geometries Enables you to select which geometries of the part or assembly to initialize for meshing.

    If you choose Select geometries, you can view a list of imported geometries eligible for initialization by clicking Show advanced tree selection to open the Body selection dialog box. You can filter and select your geometries from this dialog box.

    Note: In the case of ordered geometric sets, the app initializes all 2D and 3D geometries as supports. For more information, see Ordered Geometric Sets in the Structural Model Creation Guide.

  3. Choose the initialization method for the finite element model:
    OptionDescription
    None Creates a finite element model representation without creating a mesh. Instead, you define the mesh parameters during the creation process. This approach ensures that the created mesh is suitable for your simulation.
    Automatic Creates an initial mesh automatically according to the default mesh settings. For 2D geometries, the app creates a surface quad mesh. For 3D geometries, the app creates a tetrahedron mesh.
    Manual Creates an initial mesh based on your specifications for mesh type, element order, size, and sag ratio.
    Rule-based Creates an initial mesh based on a set of parameters in a meshing rules document that you select.

    For more information about meshing rules, see Creating and Modifying Meshing Rules.

    Procedure-based Creates an initial mesh based on a set of initialization instructions in a Visual Basic script. When you choose procedure-based initialization, you must also define the inputs for the initialization script using a meshing rules document. For more information about procedures, see About User Procedures in the Model Assembly Design Guide. The status icon next to the Define inputs button changes from red to green once you define all the required inputs for the procedure.
  4. If you selected the Manual initialization method, you must specify the following parameters:
    1. Select the Mesh type.
    2. Select the Element order, linear or quadratic.
    3. Specify the element Size.

      The mesher might vary the element size to improve quality, conformance to geometry, or other parameters.

    4. If you selected Sweep 3D Mesh for solid geometries, specify the Number of layers.
    5. If you selected any other mesh type, specify the Sag ratio.

      The sag ratio controls the degree of conformance between the mesh and curved geometry. It is the ratio of the maximum distance between an element edge and the geometry to the length of the element edge.

    6. If your model includes surface geometries without a defined thickness, specify the Thickness of the shell section.
    7. Select Create knowledge parameters to create Knowledgeware parameters.
  5. Optional: To choose new mesh quality criteria, select the Select specific quality criteria option and open a saved quality criteria file.

    By default, the criteria specified in the Simulation > Quality options (Me > Preferences) are used.

  6. Click OK.

    You should always use the Mesh Creation app to review the mesh. You can then edit the mesh or delete it and create a new one that is suitable for your simulation.

The FEM representation is created and displayed in the tree.

Finite Element Model00001371 contains two sets: Nodes and Elements and Properties. You can then create meshes (under the Nodes and Elements set) while staying in your current modeling or scenario app; for more information about creating meshes, see Meshing Geometries. To create meshes, you must enter the Mesh Creation app to access the finite element representation tools.

To enter the Mesh Creation app, double-click the finite element model representation or an element belonging to the finite element model representation:

  • If the product contains only one 3D shape, you enter the Mesh Creation app directly. The finite element model representation is linked automatically to the 3D shape.
  • If the product contains several 3D shapes, the FE Model Management dialog box appears to let you link each 3D shape to the finite element model representation.

    See Managing 3D Shapes within a Finite Element Model Representation in the Structural Model Creation Guide.