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Goal of this tutorial
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Training:
Relevant data for this tutorial:
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Step 1: Start MSC Apex Generative Design
The program starts and you can directly create your optimisation model
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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, .xt, .step, and .sldprt files into the program.
First of all, import the existing assembly in which you want to replace one ore more contains the to be consolidated parts (the colours are changed to distinguish the parts better)
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In this case there are three parts that are to be consolidated and one part that is to be retained
Create initial Design Space Bounding Box
Open the Optimisation Tools and click on the Design Space Tool Tool in the Optimisation Tools
Choose the option second method Create Design Space enclosing parts and choose select the three parts you want to consolidate
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You can choose the Alignment Type and an Offset Factor in the Advanced Properties. In this case an offset percentage of 5% was chosen to give the optimiser more room to operate.
The input is confirmed and the Tool creates a new part with the initial Design Space
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Create Access and Clearance Regions
Next some help geometries are created that will be subtracted from the initial Design Space. For these steps the Design Space is hidden.
Non-Design Spaces are created where the exact Geometry after the optimisation is needed
With the Offset-Method of the Non-Design Spaces Tool the six Non-Design Spaces are chosen as shown in the picture (offset of 2 mm)
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After this the Access Regions based on the Non-Design Spaces can be created.
Therefore, the Access Region Tool in the Optimisation Tools is activated
A sufficient extrude Distance is entered and the face of the Non-Design Space is chosen to create the according Access Region
It’s recommended to choose a scaling factor for the Access Regions to have a little bit extra space for the assembly work later on (like 1.1)
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The inner surface of the Access Region is defeatured to create one filled volume. To ensure that there is also some free space on the other side, the Push/Pull Tool can be used. Drag the surface 20 mm in the positive y-direction.
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The Bracket is subtracted from the Access Region to ensure that the Non-Design Space isn’t Part of the Access Region solid
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With the same technique all Access Regions can be created. The result looks like the picture below
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Next the Clearance Region for the Sensor and the force input and the Access Region for the Sensor are defined
The For the Sensor the Clearance Region Tool is used with an offset of 0.3 2 mm. All faces except the one that faces towards the attachment point is chosen.
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To create the Access Region the Access For the force input the Clearance Region Tool is used again - only this time the “cross section” method
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All help geometries are created and they can be subtracted from the initial Design Space to create the final Design Space. Start by subtracting the Access Regions.
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Then subtract the sensor geometry. The corresponding Clearance Region is automatically subtracted as well.
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The final Design Space is created and looks like the picture
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Definition of final Non-Design Spaces
Next the final Non-Design Spaces are defined using the Offset Method on the surfaces of the final Design Space
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with an offset of 3 mm to ensure that there is enough space around it. Only the faces around the middle of it are chosen, because the rest is already covered with the access regions. The force input is a Retained Volume in this optimisation. It should always be connected to the Design Space via Non-Design Spaces (including Machining Allowances).
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To create the Access Region the Access Region Tool is used again - only this time the “cross section” method
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Definition of Machining Allowances
Machining Allowances should be applied to every functional surface. Adjacent Faces should be selected at once, to create one coherent Machining Allowance. Therefore, the automatic execution mode can be turned off.
Tip: To have an easier access to the Non-Design Spaces choose the picking Filter “Cells” and hide the Design Space Cell so that only the Non-Design Spaces are visible. Simply choose a whole Non-Design Space by drawing a rectangle like shown in the picture below.
Now your Assembly should look like this
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Note: Ensure that all your parts (Including the Design Space and the Access Regions) belong to the same assembly!
GD Configuration Tool
The GD Configuration Tool is used to create the Design Space for the optimisation considering all the previously defined geometries. Loads and Boundary Conditions applied to Retained Volumes are also transferred to the optimisation model and can be activated in the Loads and Constraints Property panel for the matching load cases. There are 7 different groups to which the geometries can be sorted to:
Design Space
Non-Design
Retained Volumes
Excluded Volumes
Access Region
Clearance Region
Machining Allowance
Design Space
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Non-Design Spaces
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Retained Volumes
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Excluded Volumes
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Access Regions
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Clearance Regions
Note: The prior defined Clearance Regions are automatically defined after you choose the corresponding Retained and Excluded Volumes
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Machining Allowance
Note: The prior defined Machining Allowances are automatically defined after you choose the corresponding Non-Design Spaces
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Click Create Configuration and a GD Configuration will be created
Click Apply Configuration and the tool executes all necessary Boolean Operations
The final Design Space is created
For the next steps hide all the other Parts of the Assembly except for the Design Space.
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You should also hide the Machining Allowances of the active Design Space to have better access to apply the loads & boundary conditions.
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You can see the included parts of the GD Configuration by double clicking the GD Configuration in the Model Browser
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To get an overview of the GD Configuration right click on this and choose Edit. A window opens where you can see the chosen geometries included in the configuration.
You can also change your configuration here and apply it again to create a new Design Space with updated geometries
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Create the material in the Materials editor and assign it to the Design Spaceand create a material for the Retained Volume and assign it
The specific values needed are the Young's Modulus (70000 MPa), Poisson ratio (0.27) and Density (2.7e-6 kg/mm3)
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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.
Note: Because we used a GD Configuration and defined the force input as retained part we can apply forces to the part which will be transferred to the optimised geometry during the optimisation
In this case four forces and one moment are defined. The first two are applied on both of the upper Non-Design Spacesthe retained volume and the last three on the Non-Design Space that is connected to the sensor:
Name | Force/Moment/Pressure/Gravity | Direction | Value in N; Nmm |
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Force - Moment 1 | Force on |
Retained Volume | Fy; Fz | -1000; 1000 |
Force - Moment 2 | Force on |
Retained Volume | Fx; Fy; Fz | 600; -800; -200 |
Force - Moment 3 | Force on |
Non-Design Space | Fy | -500 |
Force - Moment 4 | Force on |
Non-Design Space | Fx; Fy; Fz | 150; -200; -100 |
Force - Moment 5 | Moment on |
Non-Design Space | Mz | -2000 |
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Three constraints are created and attached on the Non-Design Spaces on the lower side:
Name | Direction |
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Constraint 1 | x, y, z (=0) |
Constraint 2 | x, y, z (=0) |
Constraint 3 | x, y, z (=0) |
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Step 4: Definition of 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 Eventscan be changed by adding/deleting Eventsto the GD Scenario. The assignment of the boundary conditions to the Eventscan 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 Eventindividually.
Active in Event1: Force-Moment 1, Force-Moment 3, Force-Moment 5, Constraint 1, Constraint 2 and Constraint 3
Active in Event1 Event2: Force-Moment 2, Force-Moment 4, Constraint 1, Constraint 2 and Constraint 3
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Step 5: Definition of optimisation parameters
The optimisation parameters are selected in the Studies Area as well.
Select the Strut Density: Medium
Select the Shape Quality: Balanced
Set the Complexity Setting: 1622
Enter theStress Goal: 17 MPa
Don’t forget to save the project!
Step 6: 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.
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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, Stress Goal and Complexityto influence the results and try out different options
The Complexitycan be increased for a higher resolution and more detailed result (increased calculation time!)
The Strut Densityinfluences the structures which are formed during optimisation
The whole MSC Apex Generative Design project with all results can be downloaded here:
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