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 and Usage of a Startspace.
Restart, Usage of a Start Space & Influencing the Strut Density
To influence the Strut Density even further, changes of the number of iterations, stress goal percentage 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.
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. Therefore, the unit of the exported STL-file needs to be in the same unit as the rest of the model. 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.
This way a two-stage optimisation is also possible. An already optimised geometry can be changed (adding a strut, removing a strut) and the optimisation can be started anew. 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 |
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