Beam to shells

[Drej]

Hi!

Just wondered if anyone knows what exactly happens in an FE program when one end of a beam element is joined to one node of a shell element and loaded? i.e. how will the JOINT between the two react? Will it be a pinned joint? Will it be encast? How will it affect the modal response?

Any advice would be much appreciated.

-- DREJ --

 

[EdR]

Drej:

Assuming you have properly connected the dof (i.e. particularly the rotations) the response will be exactly the same as for any other connected nodes (regardless of whether loaded or not). It will NOT be pinned unless you have specified some of the joint dof to be pinned. All responses, including modal, should be OK assuming other modeling parameters are OK....

Hope this helps..

Ed.R.

 

[GeraldV]

Just be carefull with connecting a beam to the shell normal, a shell has no rotational stifness normal to the shell. I.e. the beam will not submit any torsion to the shell.

Regards,

Gerald

 

[KSWpe]

Just an addendum to Gerald's warning. Some programs put ficticious (Zienkiewicz) torsional stiffness (normal to the plate) to avoid singularities, so the problem might not fail with a beam inducing a torsional load into the plate - but the results would be meaningless.

 

[bsantana]

As mentioned by other posters, you can connect a beam element node to a shell element node. If you connect to only one node on the shell element, however, you will introduce a significant stress concentration at that node. A better way to model is to determine what DOFs you want to transfer and use rigid links to also connect the beam element node to adjacent shell/plate element nodes. You would release the DOFs at ends of the rigid link for forces you do not want to transfer. In essence, you are spreading the concentrated forces at the connecting end of the beam element to an "area" of the shell/plate structure. Remember that a beam element is only a line. Hope this adds a little to previous answers you have received.

B Santana

 

[Drej]

Thanks everyone for the advice - much appreciated!