Goal of this tutorial
Get to know the optimisation model setup with symmetry constraint
Training:
Relevant data for this tutorial:
Step 1: Start MSC Apex Generative Design 2021
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, .xt, .step, and .sldprt files into the program.
Import/create the Design Space including the Non-Design Spaces in MSC Apex Generative Design as one solid. For this Bridge the already prepared Design Space was imported.
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 XY and YZ planes to set up the symmetric optimisation.
Non-Design Spaces have to be selected using the Non-Design Spaces Tools. Therefore, the Design Space Object can be hidden. In this case the top plate as well as the foot are directly selected as Non-Design Spaces.
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.
In this case a value of 1 mm was chosen. How much Machining Allowance is necessary, depends on the dimensions of the part and the manufacturing process/machine.
For the next steps, the Non-Design Spaces as well as the Machining Allowances are hidden.
Create the material in the Materials editor and assign it to the Design Space
The specific values needed are the Young's Modulus (192372 MPa), Poisson ratio (0.3) and Density (7.97e-6 kg/mm3)
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 one force is defined (on the top plate volume):
Name | Force/Moment/Pressure/Gravity | Direction | Value in N |
---|---|---|---|
Force - Moment 1 | Force on cell | y | -4000 |
One constraint on the foot is created and attached on the Non-Design Space:
Name | Direction |
---|---|
Constraint 1 | x, y, z (=0) |
Step 4: 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 Constraint 1
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: 14
Enter theStress Goal: 50 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.
The optimisation is finished after 64 iterations (Shape Quality: Balanced).
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
The optimisations below show the influence of the Strut Density when nothing else is changed.
Step 7: 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 picture below shows the stress distribution with a scale spectrum from 0 to 2 times the stress goal, which is a good fit for all optimisations. This displays the even distribution of the selected stress goal with the colour range of green and critical points are viewable in red.
The mass of each iteration can be visualized with a diagram
The whole MSC Apex Generative Design project with all results can be downloaded here: Coming Soon!
You might also be interested in these tutorials:
Generative Design - Jet Engine Bracket
Generative Design - GD-Bracket
Restart Optimisation
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