Tensegrity

[conor_coburn]

I am trying to model a Tensegrity frame with cables, but cant get it to stabilize, the deflections are too high meaning i am not modeling correctly i have the cables modeled with length. Link below is to model.

https://www.dropbox.com/s/b6827pfhnj43utn/T_Test4.rtd?dl=0

[Simau]

@conor_coburn 

Try with this cable setup

[conor_coburn]

Thanks, tried that, but used -0.001, got it down to 81mm. Still too much movement, these things are suppoed to be stable and more stable if you apply more prestress. Any other ideas? 

[Simau]

@conor_coburn

Try this if it fit your need, if not what deformation do you expect

[conor_coburn]

In theory if its a Tensegrital frame i should be getting very little deflection. tensioning the cables is supposed to achieve this. Tensegrity 

[Krzysztof_Wasik]

Hi @conor_coburn 

I think that there is problem with your geometry concept. I have tried with geometry from your link and results are as expected.

In your model, cables do not have significant influence on results since deformation is the same for model with deleted cables.

[conor_coburn]

I could well believe that the results are no different with or without the cables, but that is not supposed to be the case due to tensegrity. See link https://youtu.be/xDNohDRWTvU 

I am doing this for an Artist who wants to put about 30kN onto one of these frames, Based on the Wikipedia blog on tensegrity, if you pre-tension the cables the frame gets stiffer. But analysing the way i am, i cant seem to get the frame to stiffen, if i apply pretension i just put the model out of balance. If i play with the cable length best i seem to be able to do is get deflection of 81mm which seems to much. I need to find a way to get the cables to work. 

[Krzysztof_Wasik]

Hi @conor_coburn 

I have checked link you have suggested. Presented structure geometry does not correspond to your model. I would only like to say that tensegrity "effect" may not work for this (yours) specific geometry.