Wind loads and cross-section optimization

Dear experts,

I´m trying to include wind loads in the optimization process for some lattice structures using OptiCroSec component. Unfortunately, the wind load depends on cross-section external diameter.

Is it possible to consider some wind pressure [kN/m2] instead of line force [kN/m] in OptiCroSec to automatically update wind loads during the cross-section optimization process?

At this moment I´m using a Block type Beam Load (global proj. enabled), but the line force [kN/m] must be predefined… In other words, I have to manually update the wind exposed areas of the beams until convergence.

Any more elegant workaround in Karamba?

Thanks a lot!

Hello @Vigardo,
currently (Karamba3D 2.2.0) it is not possible to define loads that depend on the chosen cross section.
A workaround could be to do multiple OptiCroSec-calculations with updates of the loads in between.
– Clemens

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Maybe in this case it would be better to use an algorithm, like galapagos or octopus than OptiCrossSection
I don’t use OtiCrossSection very much and prefer to do optimization research with several goals: displacements according to the type of elements, work rate, shape research (number of beams, centre distance, etc.). And make these analyses with Octopus.

Thanks Jacques for your interesting contribution.

If the number of dimensions to optimize is not very high Galapagos and Octopus will do the job. Goat (goat | Food4Rhino) and Oppossum (Opossum—OPtimizatiOn Solver with SUrrogate Models | Food4Rhino) are also very good alternatives.

However, when one has several different types of bars the best choice seems to be Karamba´s OptiCroSec component. It is very fast and reproducible.

For my particular case, I use a combination of both OptiCroSec (for Cross-sections optimization) and Galapagos or Opossum for shape optimization (as you said, i.e. for distances, shapes, number of floors, etc.)