complete optimisation pending

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, .xt, .step, and .sldprt files into the program.

• First of all, import the existing assembly which contains the to be consolidated parts (the colours are changed to distinguish the parts better).

• In this case there are three parts that are to be consolidated and one part that is to be retained.

Create initial Bounding Box

• Open the Design Space Tool in the Optimisation Tools.

• Choose the second method Create Design Space enclosing parts and select the three parts you want to consolidate.

• 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.

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.

• At first we need to define regions where accessibility is needed

• Therefore we use the split tool with the offset function and an offset of 3 mm.

• After this the Access Regions based on the cells can be created.

• Therefore, the Access Region Tool in the Optimisation Tools is activated.

• A sufficient extrude Distance is entered and the face ofthe created cells 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).

• 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.

• The Bracket is subtracted from the Access Region to ensure that the Non-Design Space isn’t Part of the Access Region solid.

• With the same technique all Access Regions can be created. The result looks like the picture below.

• Next the Clearance Region for the Sensor and the force input and the Access Region for the Sensor are defined.

• For the Sensor the Clearance Region Tool is used with an offset of 0.2 mm. All faces except the one that faces towards the attachment point is chosen.

• For the force input the Clearance Region Tool is used 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).

• To create the Access Region the Access Region Tool is used again - only this time the “cross section” method.

Definition of Interfaces

• Next the Interfaces are created where the exact Geometry after the optimisation is needed.

• The Interfaces are chosen as shown in the picture with a thickness of 3 mm, a machining offset of 1 mm and an offset distance of 2 mm.

• Now your Assembly should look like this.

• 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

• Interfaces

Design Space

Retained Volumes

Excluded Volumes

Access Regions

Clearance Regions

Note: The prior defined Clearance Regions are automatically defined after you choose the corresponding Retained and Excluded Volumes.

Interfaces

• 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. You should also hide the Machining Allowances of the active Design Space to have better access to apply the loads & boundary conditions.

• You can see the included parts of the GD Configuration by double clicking the GD Configuration in the Model Browser.

• 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.

• Create the material in the Materials editor and assign it to the Design Space and Retained Volume. It is possible to create a separate material for the Retained Volume. In this case the material behaviour is Isotropic.

• The specific values needed are the Young's Modulus (72000 MPa), Poisson ratio (0.34) and Density (2.7e-6 kg/mm³).

• The Tension Strength is the maximum allowable stress for the material and is set to 460 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.

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 the retained volume and the last three on the faces of the interface that represents the connection to the sensor. Ensure to display the Design Space Solid to be able to apply Boundary Conditions.

Three constraints are created and attached on the Interfaces on the lower side:

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 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, Force-Moment 3, Force-Moment 5, Constraint 1, Constraint 2 and Constraint 3

• Active in Event2: Force-Moment 2, Force-Moment 4, Constraint 1, Constraint 2 and Constraint 3

Step 5: 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: 27

• Select the Strut Density: Medium

• Select the Shape Quality: FineTune

• Set the Complexity Setting: 25

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).

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, 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

The whole MSC Apex Generative Design project with all results can be downloaded here:

You might also be interested in these tutorials:

• Symmetry Optimisation - Bridge

• NURBS Retransition Full Workflow