Tutorial Level: Beginner 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
Press F7 to open the Demo Browser.
Double-click the Analyze Design Concept.stmod file to load
it in the modeling window.
Press F2 to open the Model Browser. Verify that the Generating
Design Concept Tutorial Max Stiffness Mass 30% result
alternative is selected.
Make sure the display units in the Unit System Selector are set to
MMKS (mm kg N s).
View and Refine the Optimization Results
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.
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
Select the Smooth Results checkbox on the Shape
Explorer. (This setting may already be selected if you used it previously during
the session.)
Click Smooth Results Parameters on the Shape Explorer.
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.
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.
Click in the modeling window to close the dialog.
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
Press F5 to view the Model Configuration toolbar, which appears at the top of
the Model Browser.
Deselect the rocker checkbox to configure off the
initial part. This will exclude it from any calculations.
Right-click and mouse through the check mark to exit, or double-right-click. The Model Configuration toolbar is
closed.
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.
Use the Contacts tool on the Structure ribbon to locate
and review these gaps.
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
On the Structure ribbon, click the Run Optimization button in the Analyze tool
group to analyze the modified shape.
Set the Speed/Accuracy setting to
Faster.
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.)
Double-click the name in the Run Status window to view the results in the
Analysis Explorer.
View the Analysis Results
In the Analysis Explorer, select Jump under
Load Case and select
Displacement under Result
Types.
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.
Click the button on the
animation toolbar to visualize the displacement. Click the button to pause
the animation.
With the Jump load case still selected, switch to
von Mises Stress under Result
Types.
In the Analysis Explorer,
click Show Selected Load Case and select
Hide all loads and supports.
Rotate the model to check that there are no hidden red areas.