Telescopic member connection

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Hi! I'm a bit confused on how i typically would model these type of member connections. Fairly certain this isn't what you'd call a telescopic connection either.. but i'm not quite sure what to call it so.. yeah..

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Ignoring the real life scenario of how these members interact with one another, but lets pretend for a moment i want these to be more or less rigidly connected, but only after a certain "slippage" of a few mm. There's clearly a gap in the connection in the Global X direction in the CAD image..

I'm fairly certain this can be achieved by adding a line release and adding partial activity in the applied hinge, although i'm not quite sure how to build up said hinge in order to get what i want, mostly due to lack of understanding what everything means and work in the dialog boxes..

Now..i could probably figure this out if it was just these two profiles acting as a beam with nothing else in the model to pay attention too. But unfortunately, i've got intersecting columns at a set interval with pinned end hinges. So i need this beam to be split and connected as member sets.. and well, the whole thing is starting to spiral from here, with DOF being a mess leading to model instabilities. Also, not quite sure how to get these members to connect the way they do in the model without using eccentricities?

I'd be thrilled for any thoughts on how to model this properly to:

  1. Account for slippage before activity, please share a screenshot of how one would build up the line hinge.
  2. The two connected beams are contineous member sets, so i'd have to add line releases to each segment of the total beam, right? Do i still apply the "slippage hinge" on every singel line release? or just the first / last?

I probably have more questions but i'm not really sure what end to start looking at. Any help on the matter is appreciated. I view this as a learning experience more than anything, i'll probably just remodel the cross section as a new " combined" version and apply member end hinges and move on.. but it'd be interesting to learn a few neat tricks along the way at least.

Thanks for any tips on the matter! :slight_smile:

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Hi :waving_hand:,

If you want to solve this using members, here’s how you can approach it:

  1. Model each cross-section part as an individual bar.
  2. Connect them using rigid links.
  3. After that, you can assign a line hinge to the rigid link with the corresponding allowed displacement.

:warning: Keep in mind that in this case, the shear force (shear flow) will not fully pass through the stiffening (green-marked) part of the profile.

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To analyze this properly, you would need a surface model:

  • Model both cross-section parts with surface elements.
  • Define the contact condition at the interface via a line hinge.
  • For the shear connection perpendicular to the green element, you can use surface contacts.

This approach allows for a more realistic simulation of the shear flow through the profile.

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