Pin connection

[azri_muin]

Hi guys,

I have some curiosity in defining pin connection, what is the best approach to define the pin connection where the pin is used to connect between two eyes, but both will be locked at both side.

(both side similar, locked with locking plate).

my question is, should we use gap contact or RBE2? and if we use gap contact, do we need to beam/bar release or constraint the nodes at the end of both pin?

Thank you in advance for your insight.

Beste regards,
Azri

 

[SWComposites]

Do you care about the local stresses in the lugs? If so, using a “wagon wheel” RBE2 will result in completely wrong stresses. Also, your mesh is not small enough in the lugs to get accurate stresses even without the rigid connections.

Gap/contact where?

 

[azri_muin]

Thanks SWComposites for your prompt response.

Yeah i am checking the stresses in the lugs. From figure before, i am using the gap element as contact to connect both lugs (the option "GAPS AS CONTACT" in the BULK DATA section also enabled) not RBE2 but not sure for standard practice, whether is it okay to use gap element without apply other constraint on both end of the pin.

 

[SWComposites]

Please show in a picture exactly where you have the gap element(s).
If you have an RBE2 connecting the pin to the periphery of the hole, then your lug stresses will be rubbish.
How are you modelling the pin? Beam elements?

 

[rb1957]

doesn't FeMap have a "fastener" tool ? I might use an RBE3 (which I think has no stiffness). If I'm right, the RBE2 will keep the holes exactly circular (as per the original geometry). But neither RBE will correctly model a fastener bearing on one part of the perimeter, gapping possibly on the other. But why such a concern over this ? a simple model (no hole, a simple beam for the pin) would give you the loads in the pin, then a simple hand calc would tell you the lug stresses. no?

"Hoffen wir mal, dass alles gut geht !"
General Paulus, Nov 1942, outside Stalingrad after the launch of Operation Uranus.