Kangaroo

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Kangaroo is a Live Physics engine for interactive simulation, optimization and form-finding directly within Grasshopper.

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Kinectic arch design issues or kangaroo?

by Carlor

Mar 20, 2011

Goodday,

 

After trying out a single actuated tensegrity module,I tried working on a simple arch and designing a simple 2D arch with actuators in the middle, based on a design of the ORAMBRA.

Except i can't get it to work, and i wonder if i'm doing something wrong with kangaroo again or is the 2D design just to stable to move?

The desired effect is to see how and how much the arch will move under movement of the actuators. The arch is just a example which I can base further models on, but with the same end goal.

  • In de design of ORAMBRA the outer and inner lines are cables, do I adjust the stiffness ?
  • The actuators don't seem to move in the simulation, too stiff or tolerance to high in kangaroo ?
  • Do I add a extra downward force (gravity)? 
  • ...

Thanks in advance

If you have any question or if you need more info, just shoot.

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  • up

    Carlor

    Aha, thank you very much Nick,

    however i can't seem to find my mistake, what have you adjusted, if i may ask? 

    • Added Geom out
    • Added Geom in, but didn't flatten it ?
    • Added force on the upper points of the arch
    • ?

    And indeed the important question is the actuation, which is part of my dissertation at the university.

    However the title of the dissertation is the simulation of these structure, so i would like to see my mistakes, so i can generalize to more structures.

     

    Thanks in advance !

    Mar 22, 2011

    • up

      Nick Cole

      Sorry for the slow reply. It was an insanely busy week last week.

      - The main thing i did was flatten the Force Objects input.

      - There was also a Crv box that was messing up the input for the diagonals. Don't know why, but it wasn't needed anyway.

      - Then you generally have to play with the settings for stiffness, drag and timestep to tune it to your particular model. The user manual that Daniel has been writing has an explanation about how Kangaroo works and the effect of the various settings and forces.

       

      Daniel it would be useful to have a link to your draft Kangaroo user manual on the front page of this group. Or could it go as a fixed discussion topic like Davids Galapagos explanation? Several questions have come up recently (and i'm sure many more that haven't been asked) about units and modelling real world behaviour. It would be useful to have something about this in the manual. Or did i just miss it in the first one?

      Mar 28, 2011

      • up

        Nick Cole

        It would also be really interesting to understand the difference between the different solvers and the best ways to use each of them.

        Mar 29, 2011