Goal of this tutorial
Application of the Advanced User Settings to realize unconstraint rotational degrees of freedom
Modification of remote loads to RBE2 ties
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 for example .xb, .xt, .step, and .sldprt files into the program.
Import/create the Design Space including the Interfaces (Non-Design Spaces) in MSC Apex Generative Design as one solid.
Open the Optimization Tools to select the imported Geometry as the Design Space.
Choose the material AlSi10Mg in the Materials editor and assign it to the Design Space. In this case the material behaviour is Isotropic.
The Tension Strength is the maximum allowable stress for the material and is set to 460 MPa.
Step 3: Definition of boundary conditions
Creation of the load
On the middle cylinder surface a direct load is created.
Name | Force/Moment/Pressure/Gravity | Direction | Value in N/Nmm |
---|---|---|---|
Force 1 | Force on faces | z | -5000 |
Creation of dummy loads to be modified to displacement constraints
Currently, the creation of displacement constraints with RBE2 ties and rotational degrees of freedom isn’t supported from the graphical user interface. To realize it dummy loads are created and modified with the Advanced User Settings.
On the outer cylindric surfaces two dummy loads are created. These dummy loads need to have a load value in a direction which will be constraint afterwards.
Name | Force/Moment/Pressure/Gravity | Direction | Value in N/Nmm |
---|---|---|---|
Force 2 | Force on faces | x | 1 |
Force 3 | Force on faces | x | 1 |
In Step 6 the dummy loads will be modified to displacement constraints with a RBE2 tie and unconstraint rotational degrees of freedom.
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.
In this case for the outer, bigger cylinders and the middle cylinder inclusive the front faces are manually selected. A Non-Design Space Thickness of 3 mm and a Machining Allowance of 1 mm is entered.
Note: the Interface Offset (usually displayed in red) is not visualized due to a limitation. The correct value will be considered in the optimisation.
On the smaller outer cylinders a Non-Design Space Thickness of 1mm and a Machining Allowance of 0.5 mm is applied. For these cylinders the “automatically create interface” option can be used by selecting the corresponding boundary conditions on these surfaces.
Step 5: 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 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.
Event 1: Force 1, Force 2, Constraint 1
Event 2: Force 3, Force 4, Force 5, Force 6, Force 7, Force 8, Force 9, Force 10, Constraint 2, Constraint 3
Step 6: Casting Design Rules via the Advanced User Settings
To change the Manufacturing Method to Casting the Advanced User Settings have to be used.
The following commands are added to the scenario:
configuration.strategy=Casting tool.tool0.draft=5 tool.tool1.draft=5 |
With the first command the optimisation strategy is set to Casting. The following commands defining tools. Each tool is one draw direction for the manufacturing process. The actual draw direction is set as a vector. For each draw direction a draft angle can be set. The draft angle (specified in degrees) is the tapering angle for walls/ribs regarding the draw directions.
In this case two draw directions are defined in positive and negative z-direction and a tapering angle of 5°.
Step 7: Definition of optimisation parameters and Generative Design Settings
The optimisation parameters are selected in the Studies Area as well.
Manufacturing Method: Generic AM
Failure Criteria: Von Mises
Safety Factor: 25
Strut Density: Medium
Shape Quality: Balanced
Step 8: Starting the optimisation and visualize 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.
Step 8: Visualization of Stresses & Displacements
Inside the Post-Processing the von Mises stress and the displacements are visible for all iterations and for every Event
The Scale can be influenced individually
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:
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