...
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.
...
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 |
Soft Symmetry
The soft symmetry is activated per default. It influences the design generation so that the part is symmetric in all three dimensions if they were symmetric in the respective dimension to begin with. This is achieved for geometrical symmetrical design spaces even without symmetric LBCs and the hard symmetry constraint.
Equivalence Delta Value:
This governs how far the optimization value of two symmetric elements is allowed to differ while still being considered equivalent. In theory any value works: the higher the value the more zealously the algorithm will try to keep Soft Symmetry, possibly degrading the quality of the produced geometry compared to a non-symmetric one. The default value is 1e-6.
Attempt Soft Symmetry:
Whether or not Soft Symmetry is attempted at all can be (de)activated here.
off: Soft Symmetry is deactivated.
always: Soft Symmetry is always on.
dynamic: The optimisation will start with Soft Symmetry activated but turn it off once no dimension’s symmetry can be salvaged. Note that “dynamic” will never turn it back on once it has turned it off once.
Soft Symmetry Threshold:
Specifies how many asymmetric voxels are sufficient for the "dynamic" setting of attemptSoftSymmetry to turn off soft symmetry. Values between 0 and 1 are allowed, where the number represents the proportion of voxels.
The default settings can be changed with the following commands:
...
configuration.equivalenceDelta = 1e-6
configuration.attemptSoftSymmetry = dynamic
configuration.softSymmetryThreshold = 0