Grashopper, Karamba3D joints and supports in bowstring truss bridge

[Viktor_Eriksen]

Hi,

I am fairly new to rhino, grashopper and karamba3D. I have modelled a bowstring truss bridge and now want to connect the beams with joints that a hinged.

The problem is, that in the nodes where the supports are located, it seems that a negative moment of inertia occours within the trusses and some of the beams.

This I would not like, as the connection should be hinged and not pinned. Can anyone help me with solving this problem?

Assignment A2, bro-design vers. 3.gh (42.5 KB)

[matttam (Matthew Tam)]

You havent defined any releases at those nodes so of course there are moments at your supports. If you use the beamjoints component to define joints at every node then there would be no moments at your support. Be aware that when releasing all three rotation axes will result in a kinematic structure.
Assignment A2, bro-design vers. 3-mt.gh (54.7 KB)

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