Tutorial: Generating CAD and Analyzing Results

Learn how to fit a PolyNURBS to a smoothed result.

In this lesson you will learn how to:
  • View and smooth an optimized shape
  • Generate CAD by fitting a PolyNURBS to the smoothed result
  • Modify the CAD to better contact the non-design spaces
  • Analyze the modified shape and view the results


Open the Design Concept Model

  1. Press F7 to open the Demo Browser.
  2. Double-click the Analyze Design Concept.stmod file to load it in the modeling window.


  3. Press F2 to open the Model Browser. Verify that the Generating Design Concept Tutorial Max Stiffness Mass 30% result alternative is selected.


  4. Make sure the display units in the Unit System Selector are set to MMKS (mm kg N s).

View and Refine the Optimization Results

  1. On the Structure ribbon, click the Show Optimization Results button in the Optimize tool group to view the Shape Explorer for the optimization that was previously run and saved with the model.


    Tip: To find and open a tool, press Ctrl+F. For more information, see Find and Search for Tools.
  2. Position the Topology slider on the Shape Explorer two ticks from the far right. This is the point at which the generated shape is fully connected, which is important when fitting PolyNURBS to the result. Your analysis results and CAD conversion will vary depending on where you position the slider.


Smooth Results and Fit PolyNURBS

  1. Select the Smooth Results checkbox on the Shape Explorer. (This setting may already be selected if you used it previously during the session.)
  2. Click Smooth Results Parameters on the Shape Explorer.
  3. Experiment with the options on the dialog and see how this changes the smoothness of the optimized result.
    • Drag the slider to the right to increase the smoothness.
    • Maintain part volume while smoothing is the default option. Ignoring the part volume tends to provide even smoother results, but material may appear thin or be removed entirely in some regions.
    • Increasing Smoothing iterations setting will also produce a smoother result.
  4. This dialog also allows you to adjust settings for fitting a PolyNURBS to the optimized result. Try using the default settings first. For more information, see Fit PolyNURBS to the Generated Shape.
  5. Click in the modeling window to close the dialog.
  6. Click the Fit PolyNURBS button on the Shape Explorer. This converts the PolyNURBS to a CAD part, which appears as Part 4 in the Model Browser.

Eliminate Gaps Near Non-Design Spaces

  1. Press F5 to view the Model Configuration toolbar, which appears at the top of the Model Browser.
  2. Deselect the rocker checkbox to configure off the initial part. This will exclude it from any calculations.
  3. Right-click and mouse through the check mark to exit, or double-right-click. The Model Configuration toolbar is closed.
  4. Use the scroll wheel to zoom in on the areas where the PolyNURBS contacts the three boss parts. Notice that the PolyNURBS part has gaps near these non-design spaces.
  5. Use the Contacts tool on the Structure ribbon to locate and review these gaps.
  6. Fix these gaps using the tools on the PolyNURBS ribbon so that high stress concentration areas are not found in the subsequent analysis. For more information, see PolyNURBS.

Analyze the Modified Shape

  1. On the Structure ribbon, click the Run Optimization button in the Analyze tool group to analyze the modified shape.


  2. Set the Speed/Accuracy setting to Faster.


  3. Click Run.
    Depending on how well the cleanup went in the previous step, you may get a warning message similar to the one below. If you do, click Continue.


    A green checkmark will appear when the analysis is complete. (This may take several minutes.)

  4. Double-click the name in the Run Status window to view the results in the Analysis Explorer.

View the Analysis Results

  1. In the Analysis Explorer, select Jump under Load Case and select Displacement under Result Types.


  2. The maximum displacement shown in the legend should be approximately .5 mm, but your results will vary depending on where you positioned the topology slider and how you modified the geometry near the non-design spaces.


  3. Click the button on the animation toolbar to visualize the displacement. Click the button to pause the animation.
  4. With the Jump load case still selected, switch to von Mises Stress under Result Types.


  5. In the Analysis Explorer, click Show Selected Load Case and select Hide all loads and supports .

  6. Rotate the model to check that there are no hidden red areas.