...
With this option a terminated optimization can be continued or a two-stage optimization with varified verified optimization parameters can be done. Instead of the Design space another geometry can be chosen as the Start space. In this case the optimization starts not with the whole Design space however this Design space is still the geometry limitation for the optimization.
Restart
The Start space has to must be a STL-file. Therefore, a already optimized geometry can be exported in the Post Processing. In this case iteration 22 from the symmetrical Bridge will be used.
...
Attention: The STL-file for the Restart has to must be exported in SI-Units (Meters).
...
In this example the Bridge should be restarted with the same optimization parameters as the first optimization excluding the already done iterations. This can be done when an optimization is terminated and restarted at another time. Therefore, the missing number of iterations for the parameters Strut Density: Medium and Shape Quality: Balanced are added to the Advanced User Settings. Which number of iterations and which stress percent goal should be input for each resolution level can be found here.
In this case the optimization will restart at iteration 22, thus the following 42 iterations have to must be added to reach the total number of 64 iterations (Shape Quality: Balanced). Therefore, the UpSampleConfig in the picture above is added (18 iterations at resolution level 2, 20 iterations at resoultion resolution level 1 and 4 iterations at resolution level 0).
After adding these commands to the Advanced User Settings the optimization can be started. The first iteration of the restarted optimization will be the imported Start space.
...
Two-stage optimization
A seconed second possibility is to perform a two-stage optimization. Instead of a simple restart with the same optimization parameters the parameters can be varied.
...
Skipping the coarse resolution level and calculate directly on the finest resolution level with an early iteration from a former optimization, if a very fine high-resoltion resolution level is desired
Vary the value for the stress goal to keep the overall geometry with more or less material
Modify an optimization output (remove or add struts) and restart with this modified geometry
Creation of a lattice stucuture structure of an optimization output and restart to optimize the lattice
...