With the Advanced User Settings the optimisation parameters can be influenced even further than the options Strut Density and Shape Quality. Furthermore, a few unsupported options are available using the Advanced User Settings like Restart, Usage of a Startspaceand activate automatic Non-Design Growth during the optimisation.
The Advanced User Settings can be added to a Scenario by right clicking on this and selecting the option as shown in the picture below.
The appearing text field can be used to add Advanced User Commands to the current Generative Design Scenario.
Restart, Usage of a Start Space & Influencing the Strut Density
To influence the Strut Density even further, changes of the number of iterations, Event Safety Coefficient and number of resolution levels can be made. These settings overwrite the selection of the Strut Densityand the Shape Quality as they are only default settings for the ones described here. The table gives an overview of the default settings:
Input Commands | Explanation |
|---|---|
schedule.level.0.iterationCount = 19 schedule.level.1.iterationCount = 20 schedule.level.2.iterationCount = 20 schedule.level.3.iterationCount = 5 | Specify how many iterations are calculated at which resolution level. Note that convergence should be achieved at each level. Default settings medium: 19, 20, 20, 5 Default settings sparse: 15, 40, 4, 5 Default settings dense: 9, 10, 40, 5 |
schedule.level.0.eventSafetyCoefficient = 0.3 schedule.level.1.eventSafetyCoefficient = 0.4 schedule.level.2.eventSafetyCoefficient = 0.9 schedule.level.3.eventSafetyCoefficient = 1 | Scaling factor for all events' safety factor. Default settings medium: 0.3, 0.4, 0.9, 1 Default settings sparse: 0.6, 0.9, 0.95, 1 Default settings dense: 0.1, 0.25, 0.5, 1 |
The software uses four resolution levels from coarse to fine (level 0: coarse - level 3: fine). The number behind the level indicates the number of iterations calculated on this resolution level. To remove or skip a resolution level the value can be set to 0. Moreover, the Event Safety Coefficient for each resolution level can be changed. This coefficient is a scaling factor for the safety factor. More information about the safety factor, stress, failure criteria and resolution here.
To set up these additional parameters, the Input Commands (left side of the table) need to be added to the optimisation model in the Advanced User Settings Text Field. In the picture below an example is shown. By adding these Advanced User Settings, the first (coarse) resolution level will be skipped and the optimisation starts directly at the second level. You might want to add more iterations to the remaining levels to give the optimisation the chance to reduce the material accordingly and reach a convergence in each level. Especially level 2 can use more iterations in this case.
Restart (Start Space)
With the Advanced User Settings a Restart is possible. A Start Space needs to be chosen with which the optimisation will re/start.
Therefore, an already optimised STL-file is needed as a Start Space. This can be exported directly from the post processing and be selected as a Start Space by clicking on the browse button. Therefore, the unit of the exported STL-file needs to be in meters (SI-Units). In most cases the Strut Density and Shape Quality settings must be changed as well using the Advanced User Settings. For a restart the same resolution level and number of to be completed iterations have to be filled in. You can find a Tutorial to how to perform a Restart here.
This way a two-stage optimisation is also possible. For a two-stage optimisation the resolution level and number of iterations must be chosen wisely and will need some fine tuning.
A Start Space can be marked as a Non-Design Space, thus the Start Space cannot be removed during the optimisation and will be part of the final design. Therefore, the following commands (where StartCandidate is the name of the Start Space file) need to be added as well:
geometry.StartCandidate.path = StartCandidate.stl |
Activate Automatic Non-Design Growth
All areas applied with a boundary condition are automatically Interfaces. With an Interface the surface will grow a little bit beyond the Design Space boundaries to ensure a trouble-free and clean intersection. It is also possible to detect all Non-Design Space surfaces which are at the same time Design Space limits and let them grow automatically. This option results in a different connection between the Design Space and the Non-Design Spaces/Interfaces. Both results can be viewed here.
If the connection of the automatic Non-Design Growth is preferred, it can be activated with the following command:
configuration.autodetection.positiveNonDesignDirection = true |
|---|
Sometimes this can lead to issues which are described here.
Add Comment