Wind loads and cross-section optimization

Grasshopper Karamba3D
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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!

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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

1 Like
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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.

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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.)