Goal of this tutorial
Get familiar with the symmetry function
Training:
Relevant data for this tutorial:
Step 1: Start MSC Apex Generative Design
The program starts and you can directly create your optimisation model
Step 2: Model generation
You can either create the geometry directly in MSC Apex Generative Design or import already existing files. You can import .xb, .step, and .sldprt files into the program.
Import/create the Design Space including the Non-Design Spaces in MSC Apex Generative Design. For this Pedal the already prepared Design Space and Non-Design Spaces were imported.
The CAD-file includes several solids. The file Pedal_body_1 is used to split the upper surface of the pedal to create the area for the load application point. Therefore, open the Split Surface Tool in the Geometry Edit Tools and select the top left surface as the split surface. Now select all curves that separate the surface as in the picture below.
Open the Design Space Tool in the Optimization Tools to select the imported Geometry as the Design Space. Activate the Symmetric Design Constraint and select the XZ plane to set up the symmetric optimisation.
The other solid of the pedal Pedal_body_1 is no longer needed and can be hidden or even deleted.
Create the material Steel in the Materials editor and assign it to the Design Space. In this case the material behaviour is Isotropic.
The specific values needed are the Young's Modulus (192372 MPa), Poisson ratio (0.3) and Density (7.97e-6 kg/mm3).
The Tension Strength is the maximum allowable stress for the material and is set to 320 MPa.
Step 3: Definition of boundary conditions
Go to the Loads & Boundary Condition Tool to enter the loads and fixations. Displacements, Forces, Moments, Gravity and Pressure Loads can be applied using different selection options.
In this case only one force is defined on the contact plate with the foot:
Name | Force/Moment/Pressure/Gravity | Direction | Value in N |
|---|---|---|---|
Force-Moment1 | Force | y | -1000 |
One constraint is created and attached on the inner surface of the cylinder:
Name | Direction |
|---|---|
Constraint 1 | x, y, z (=0) |
Step 4: Interface Creation
Interfaces have to be created for every functional surface - so every surface where a boundary condition is applied to. With this Tool an offset to the inside with the input “Non-Design Space Thickness” and an offset to the outside with the input “Machining Allowance” is created. The Offset Distance is expanding the Interface to the set value to create material on front faces.
All surfaces on which a boundary condition is applied can be selected directly as an interface with the “Select Faces from Loads and Boundary Conditions” button. The Boundary Condition surfaces will be highlighted and can be selected/deselected. With “Apply” the Non-Design Space Thickness, Machining Allowance and if available Offset Distance values will be applied to the selected surfaces.
One Interface is created on the force application surface. Therefore, an Non-Design Space Thickness of 1 mm and a Machining Allowance of 1 mm is entered. Now select the surface and confirm the selection (MMB).
One Interface is created on the inner surfaces of the fixation. Therefore, an Non-Design Space Thickness of 2 mm and a Machining Allowance of 1 mm is entered. Now select the inner surfaces and confirm the selection (MMB). The outer most surface of the Fixation is not selected because is would create material outside of the Design Space.
Step 5: Definition of Events (load cases)
The next steps are defined in the Studies area.
All boundary conditions must be assigned to the specific load cases, which are defined as Events. The number of Events can be changed by adding/deleting Events to the GD Scenario. The assignment of the boundary conditions to the Events can be made in the Loads & Constrains Window. The already created loads and constraints that concern the Design Space are listed in this window and can be activated for each Event individually.
Active in Event1: Force-Moment 1 and Constraint1
Step 6: Definition of optimisation parameters
The optimisation parameters are selected in the Studies Area as well.
Manufacturing Method: Generic AM
Failure Criteria: Von Mises
Safety Factor: 6,4
Select the Strut Density: Medium
Select the Shape Quality: Balanced
Set the Complexity Setting: 10
Don’t forget to save the project!
Step 7: Starting the optimisation and visualizing the results
If all data is correct, the optimisation can be started and tracked in the Post Processing. The Analysis Readiness function checks if all information is provided and the optimisation can start.
All result iterations are displayed as soon as they are available. Furthermore, you are able to stop the optimisation in this selection area. However, a Restart is not directly possible.
The optimisation is finished after 64 iterations (Shape Quality: Balanced).
You can check the status of the optimisation in the GD Status and get more information on Warning and Error messages. This can be done directly in the Post-Processing as well as in the Studies tab for an optimisation that has already run.
Generative Design
You can always change the Strut Density, Stress Goal and Complexity to influence the results and try out different options
The Complexity can be increased for a higher resolution and more detailed result (increased calculation time!)
The Strut Density influences the structures which are formed during optimisation
Step 8: Visualization of Stresses, Displacements & Mass
The legend can be influenced in different ways. You can add and reduce the stress/displacement steps, enlarge different steps and set new minimum and maximum values. The mass of each iteration can be visualized with a diagram.
You can go back to the model setup by clicking the Exit button in the right bottom corner.
The whole MSC Apex Generative Design project with all results can be downloaded here:
Coming Soon!
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