Cables in a paraboloid

Hi all.

Im pretty new at grasshopper/ karamba, so hope you guys will help me.
Im working with a paraboloid, where the mesh i made of cables, and the ring is made of a circular steel profile.

My problem is to force the cable to work like cables, (pure tension beams). As i can figure out, there is not a cable component in karamba, so i have tried different kind of things, but nothing seems to work.

Hope you can help me, any help will be appreciated.

Best regards
Christian Svarre