Kangaroo and Galapagos tutorials/manuals/whatever?

Hi,

I apologise for these stupid question, but does anyone know some links on how to work with Kangaroo and Galapagos?

I wanna get a better understanding on how to operate with these tools and figure out their limits.

Thanks to everyone.

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Permalink Reply by dani bas on December 27, 2010 at 8:49am

up!

i am also interested

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Permalink Reply by Nick Cole on December 28, 2010 at 3:29am

This probably isn't the best thing to start with but you might be able to work your way through it. I'm assuming that you're talking about using Kangaroo and Galapagos together rather than just advice on how to use one or the other. Once you understand how to use Kangaroo and Galapagos separately then combining the two is quite easy.

In the attached file i've set up the geometry for a simple roof mast structure that i've been working on. I've plugged the geometry into Kangaroo with a single point load at the tip of the mast structure. Then in the output i've used the final lengths to calculate the member forces and used this to display coloured and sized tubes to show the forces in the members. I've found this gives really good visual feedback on how the structure is behaving as you alter the sliders.

What i wanted to do with this model was to find the most efficient geometry for forces and material. To do this i've calculated the sum of the forces times the lengths and used this number as the Galapagos fitness function. i.e. I want Galapagos to minimise Sum(F x L). The trick to letting Galapagos talk to Kangaroo is how you set the iterations for Kangaroo. If you look at the bottom of the Kangaroo box, rather than plugging in the timer, i've set a series box to count Kangaroo through a set number of iterations (you need to play around with how many iterations you need to get your particular model to become stable). Kangaroo then outputs the geometry for every one of these iterations as a separate branch so you need to filter out the branch that you're interested in. Doing it like this, Galapagos only ever sees the final 'steady state' solution rather than everything inbetween.

You can use this to minimise deflection of a particular point or series of points or stresses or.... whatever you can think of! Next on my list is to set up an extra set of variables for the member stiffnesses so that it can optimise stresses by also changing the properties rather than just the forces (current model has all stiffnesses the same). I'd also like to loop the output back into the input so that Kangaroo can use the forces to feedback into the selection of member stiffnesses itself.