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Step 1: Start MSC Apex Generative Design
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You can either create the geometry directly in MSC Apex Generative Design or import already existing files. You can import .xt, .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 Bracket the Design Space was imported.
The CAD-file includes several solids. The desired Desin Design Space, as well as the dummy part for an electric motor and the needed screws to connect the parts. We will use these as retained volumes in the Retained Volumes later on in the optimisation.
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.
Create the material Steel, Pa12 and Aluminium in the Materials editor. Assign PA12 to the Design Space, Aluminium to the Motor Housing and Steel for the Screws.
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.
Name | Young’s Modulus | Poisson ratio | Density | Tension strength |
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Steel | 192.000 MPa | 0,3 | 7,97 g/cm³ | 515 MPa |
Aluminium | 72.000 MPa | 0,34 | 2,7 g/cm³ | 200 MPa |
PA12 | 1.700 MPa | 0,39 | 0,9 g/cm³ | 42 MPa |
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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 we are applying one force is defined and one moment on the contact plate with the footelectric motor:
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Name | Force/Moment/Pressure/Gravity | Direction | Value |
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Force-Moment1 | Moment | My | 30.000 Nmm |
Force-Moment2 |
Force | x | - |
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2.000 N |
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Four constraints are created and atteched on the four inner surfaces of the holes at the outer attachement points:
Name | Direction |
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Constraint 1 | x, y, z (=0) |
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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.
One Interface is created on the force application surface. Therefore, an Four Interfaces are created on the interfaces between the Design Space and the Motor. Thus we hide the Motor as well as the screws. A Non-Design Space Thickness and an Offset Distance of 1 3 mm and a Machining Allowance of 1 mm is entered. Now select the surface and confirm the selection (MMB).
One Interface is
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Another four Interfaces are created on the inner surfaces of the fixationfixations. Therefore, an Non-Design Space Thickness of 2 3 mm, an Offset Distance of 3 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.
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Furthermore we create two Interfaces at the bottom of the Design Space, to ensure that the fixations on the different sites are connected and there is a good interface to place the bracket later on on the ground. For this we select the two outer surfaces at the bottom and choose a Non-Design Space Thickness of 5 mm.
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Step 5: Definition of the Generative Design Configuration
In the next step the interaction between the retained parts and the Design Space ist defined. For this the Generative Design Configuration Tool is used. Start the Tool and chosse for each step the corresponding objects and click the MMB. For this configuration we just choose the Design Space for the Initial Design Space and the Motor and the screws as Retained Volumes.
Note: The prior defined Interfaces are automatically chosen after the selection of the Design Space.
After the selection click Create Configuration and Apply Configuration. After this the Gd Configuration 1 and the corresponding Generative Design Part 1 are created. If you right-click on the Configuration object and choose edit, you can validate or change your seection. It should look like this:
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Step 6: Definition of Events (load cases)
The next steps are defined in the Studies area.
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Active in Event1: Force-Moment 1 and Constraint1
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and all Constraints
Active in Event2: Force-Moment 2 and all Constraints
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Step 7: 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: 1014
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Don’t forget to save the project!
Step 8: 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.
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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.
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Generative Design
You can always change the Strut Density, Safety Factor 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 9: 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.
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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: