How to represent hinges

Gabi

The structure has parts as hinges. There are rectangles with 5 carbon fibre tubes (unidirectional), attached in a row at the edges.
Besides, inside them, it has a larger aluminium tube, in the tubes without clearance. At the ends of the larger tube, it has a head like a screw and the other,
the screw thread.
So, how do I represent this model? 'pbeam' for larger tube and rb2 at the ends? so how can i represent without loopholes between carbon fibre tubes and larger tube? 
furthermore, Can I connect the mesh from carbon's tubes  and rectangle face?

yuhaohe

You need to make engineering decisions about how to model it.

If you study object is the hinge itself, you may need to mesh the carbon fiber tubes, aluminum tubes, etc with shell elements, and apply proper contact between parts.

If you study object is something else and you just need the hinge to transfer load properly, you may simply model it as a RBE2 with torsional degree of freedom released.