When you recognize that your optimization result is growing in an inappropriate way - something is going wrong
The main reason for this is the tearing off and therefore lost connections of the Nondesign spaces on which the structural loads are applied
This can be seen in iterations where 0 MPa stresses occur (see picture below)
In the following iterations the model is growing again due to these zero stress
If a connection with the Nondesign space is created anew a stress will appear again
Solution:
The occuring stress doesn’t fit to the optimization goal
Lower the optimization goal
Increase the applied structural loads
Increase the Complexity for a higher resolution
Change strut density from sparse to balanced or dense