Tensegrity roof

Hello everyone!
I'm working on a tensegrity structure relatively simple, which is composed by compressed beams that never touch eachothers, and tense cables. This case-structure has been built, so it really works as a support system for a glass roof in Italy (image in attachment), but when I try to calculate with Karamba I have some cables compressed and it can't be possible. What do I do wrong?
Thank you.

Attachments:

152524289-33dabde0-86d7-4ce8-b501-1467b8fcd6bf.jpg, 917 KB
bronzi di riace.3dm, 39 KB
Bronzi di Riace Museum.gh, 36 KB

Replies to This Discussion

Permalink Reply by Karamba3D on March 6, 2017 at 3:50am

Hello David,

I think you forgot to add the horizontal beams in the glass plane. Without these your model is kinematic (see attached definition).

If the members you want to pretension are very stiff, then finding a state (a set of values for the prestrains) where all of them are under tension is quite complicated. The aproximate way to do it would be to calculate the tension members as trusses and then add pre-tension where compression forces result. In case of a statically indeterminate system this has to be done iteratively.

Best,

Clemens

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