Run a topology optimization to maximize stiffness and explore the generated
shape.
In this lesson you will learn how to:
Create multiple load cases with unit loads in x, y, and z directions
Create forces and supports
Apply symmetry planes
Apply a single draw direction
Run a topology optimization to maximize stiffness
Explore generated shapes
Open the Y-Bracket Model
Press F7 to open the Demo Browser.
Double-click the y-bracket.stmod file to load it in the
modeling window.
Make sure the display units in the Unit System Selector are set to
MKS (m kg N s).
Use the right mouse button and the middle mouse button to pan and rotate the
view so the y-bracket is positioned as shown below:
Define the Design Space
If not already visible, press F2 to open the Model Browser.
In the Model Browser, two parts are listed: Boss and Bracket. Click
Boss to select it.
The three cylindrical holes in the bracket turn yellow. While we will be
placing loads and supports on the boss materials, we do not want to subtract any
material from this part during optimization, so we do not want to include it in
the design space.
Right-click Bracket in the Model Browser and select
Design Space.
Click on an empty space in the modeling window. The red-brown color indicates
the area that material will be carved from during optimization.
Create a Center Hole Support and the First Load Case
On the Structure ribbon, select the Apply Supports
button in the Loads tool group.
Click on the front boss material to apply the support.
In the Model Browser, two new folders are created, one called
Load Case 1 and the other called All
Loads, Displacements, and Grounded Fasteners. Support
1 is added to both.
Right-click Load Case 1 and choose
Rename to make it editable, rename it Load
Case X, and press Enter.
The name of the load case is shown in bold, indicating that it is the
current load case. Any new loads or supports that you create will be added to it
automatically.
Apply Forces to Boss Materials
On the Structure ribbon, select the Force button in
the Loads tool group.
Click on one of the rear boss materials to apply the force.
The force is initially applied in the negative x direction. Click the
+/- icon in the microdialog to reverse it to the
positive x direction.
Force 1 appears in the Model Browser in the
All Loads, Displacements, and Grounded Fasteners
folder and Load Case X.
While the Force tool is still active, click on the other
rear boss material and use the +/- icon to reverse the
direction.
Both Force 1 and Force 2
should now be applied in the positive x direction, as shown in the image
below:
Force 2 appears in the Model Browser in the
All Loads, Displacements, and Grounded Fasteners
folder and Load Case X.
Right-click and mouse through the check mark to exit, or double-right-click.
Create the Second Load Case
In the Model Browser, right-click on Load Case X and
select New > Load Case.
A new load case is added in the Model Browser.
Rename the load case Load Case Y and press
Enter.
This is now the current load case.
We want to use the same support from Load Case X in
Load Case Y, so right-click on Support
1 in the Model Browser and select Include/Exclude from... > Load Case Y.
Check that Support 1 is added to Load Case
Y in the Model Browser.
Click the icons next to Force 1 and Force
2 in the Model Browser to temporarily hide these forces in the
modeling window.
On the Structure ribbon, select the Force button
in the Loads tool group.
Add two more forces, one to each of the rear boss materials in the negative y
direction.
Check that Force 3 and Force 4
have been added to Load Case Y in the Model
Browser.
Right-click and mouse through the check mark to exit, or double-right-click.
Create the Third Load Case
In the Model Browser, right-click on Load Case Y and
select New > Load Case.
A new load case is added in the Model Browser.
Rename the load case Load Case Z and press
Enter.
This is now the current load case.
Drag Support 1 in the All Loads,
Displacements, and Grounded Fasteners folder to Load
Case Z.
Click the icons next to Force 3 and Force
4 in the Model Browser to temporarily hide these forces in the
modeling window.
On the Structure ribbon, select the Force button in the Loads tool group.
Add two more forces, one to each of the rear boss materials in the positive z
direction.
Check that Force 5 and Force 6
have been added to Load Case Z in the Model
Browser.
Right-click and mouse through the check mark to exit, or double-right-click.
Right-click one of the forces in the Model Browser and select Show
all Forces.
Select Maximize Stiffness for the optimization
Objective.
Under Mass Targets, select % of Total
Design Space Volume from the drop-down menu and choose
30 percent.
Under Thickness constraints, increase the
Minimum to 0.015 m.
(This will speed up the optimization.)
Under Load Cases, deselect Load Case
Y and Load Case Z.
This will run the optimization with only Load Case X
applied.
Click Run.
When the run is complete, select it in the Run Status window and click
View Now to see the results.
The optimized shape
is displayed in the modeling window and is listed as an alternative in the Shape
Explorer.
Repeat the above procedure to run an optimization for Load Case Y.
Repeat the above procedure to run an optimization for Load Case Z.
The optimization runs for Load Case Y and Load Case Z appear as additional
alternatives in the Model Browser and the Shape Explorer.
Explore Optimized Shapes
On the Structure ribbon, click the Run
Optimization button on the
Optimize tool group.
Run the optimization one more time with the following settings to run all three
load cases simultaneously.
Change the Mass Targets to
20 percent of the total design space
volume.
Select all three load cases.
Click Run.
When the optimization is complete, a green flag appears above
the Optimize tool group, indicating that the run
completed successfully.
Click the green flag to view the optimized shape.
Drag the Topology slider in the Shape Explorer to
explore the optimized shape. Changing the topology adds and subtracts material,
giving you an idea of how this impacts the shape.
Note: Notice that as you drag the slider to the right, additional structures
emerge. This indicates that you need to rerun the optimization with a higher
percentage of material.
On the Structure ribbon,
click the Run Optimization button on the
Optimize tool group icon to open the Run Optimization
window.
Run the optimization with the following settings.
Under Mass Targets, change the % of Total Design Space
Volume to 30 percent.
Click Run.
When the optimization is complete, a green flag appears above the
Optimize tool group, indicating that the run
completed successfully.
Click the green flag to view a result similar to the one below:
Change the Design Space and Rerun Optimization
Select Switch to Design Spaces in the Shape Explorer to
switch back to the original design space.
On the Geometry ribbon, select the Push/Pull Faces
tool.
Reposition the model as shown below, then left-click on the right front face
and push it -0.07 m to make the design space
asymmetric.
Rotate the model, then left-click on the rear face and push it -0.03
m.
Right-click and mouse through the check mark to exit, or double-right-click.
Reposition the model as shown, then double-click one of the red symmetry planes
to activate the Symmetric tool.
Click on the red plane in the z direction to deactivate it.
Right-click and mouse through the check mark to exit, or double-right-click.
On the Structure ribbon,
click the Run Optimization button on the Optimize tool group icon to open the Run
Optimization window.
Run the optimization with the following settings.
Under Mass Targets, change the % of Total
Design Space Volume to 30 percent.
Select all three load cases.
Click Run.
When the optimization is complete, a green flag appears above
the Optimize tool group, indicating that the run
completed successfully.
Click the green flag to view a result similar to the one below:
Adjust the Topology slider in the Shape Explorer to
explore the optimized shape.