Generating Finite Element Models

This task shows how to generate a mesh model from a Structure Design model.
1. Load an existing Structure Design model, and prepare the analysis document.
  2. Create a new CATPart. In this example, its name is Proxy_1.
  3. Create an Analysis document associated with this proxy CATPart by switching to the Advanced Meshing Tools workbench in Analysis Simulation. Now save the Analysis document.

For a more detailed explanation, see Analysis User Guide.
   
  4. Insert this Analysis document into the product containing the design model.

(To do this, select the product and then select Insert - Exiting Component from the menu bar.)

NOTE:  Make sure the loaded Analysis document is empty and is not associated with other design models. You can check if the Proxy CATPart is populated from the previous execution of the command. If it is, repeat this step and load an empty Analysis document.
   

Specification tree now looks like this:
  5. Start the Structure Functional System Design workbench.

Click the Create Mesh button on the Structural Systems toolbar.

NOTE: To use the Create Mesh command, you need a license for Generative Assembly Structural Analysis (GAS) and Finite Element Model Surface (FMS).

The Finite Element Model Generator dialog box displays.
  6. Select the Finite Element Model from the specifications tree. In this example, Finite Element Model.1 displays in the Target field.
  7. Select Functional System from the Filter On drop down list.
  8. Select All in session from the Selection drop down list to add every Super Object the Available Objects list.

You can then select the appropriate objects from the Available Objects list, and push them to the Selected Objects list.

NOTE: You can also select the appropriate objects in your 3-D session, or from the specifications tree.
  9. Select the Options button.

The FEM Options dialog box appears.
   

FEM Options

you have 3 sections in the FEM Option dialog box.

  • Surface 2D Mesh

  • Beam 1D Mesh

  • Misc. Options

    •
       

    Surface 2D Mesh

    Data entered under this caption is applicable for 2D elements.

    Mesh Size :This field defines the mesh size for meshing 2D elements. This is a global value applied to all 2D elements (Surface).

    Min Hole Size :Specify the minimum hole diameter here. Holes having diameter less than the value specified in this field, will be ignored and a regular 2D mesh will be generated considering a continuous surface.

    Constraint Sag Ratio : In case of 2D elements, constraints are created along the edge. Number of constraints created is inversely proportional to constraint sag value. Constraint Sag Ratio is a ratio of constraint sag to mesh size. Default is set as 0.4.

    Mesh Tolerance Ratio : Mesh capture is performed dynamically on all the mesh parts. Capture tolerance is maximum distance for mesh capture. The Mesh Tolerance Ratio is a ratio of capture tolerance to mesh size. Default is set as 0.1.
       

    Beam 1D Mesh

    Data entered under this caption is applicable for 1D elements.

    Mesh Size :This field defines the mesh size for meshing 1D elements. This is a global value applied to all 1D elements (Beam).

    Mesh Tolerance Ratio :Specifies the Mesh Tolerance Ratio for 1D element.
       

    Misc. Options

    Plate and Stiffener Intersection Point Computation :Keep this option enabled to maintain the best mesh compatibility between 1D and 2D elements. A new point constraint is introduced to maintain the continuity at two intersecting meshing element.
      Keeping the Use Equivalent Dimension enabled you can apply the same value to selected parameters.
      10. Click OK. The mesh generation may take several minutes, depending on the model size and the performance of your computer.
    11. Switch to the Analysis workbench.