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release DOF in cooperation between plate and beam elements

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aischa2122

Mechanical
Joined
Jun 10, 2015
Messages
3
Location
PL
Hi!
I found closed thread named "Attaching Plate Elements to Beam Elements" in which rb1957 wrote something aboute release of a freedom. I'm very interested how to change relationship between plate and beam elements (release chosen DOF). My construction is 3d frame, and roof (plate elements) can't be part of load-bearing structure. Look at the picture below.
frame_fyy3hw.png

I want to release all rotational degrees and some translation degrees along chosen curves.

I don't know how to do it. I really appreciate any tips and tricks.
Regards!
 
the problem is that solid elements don't (generally) support rotational freedoms at their nodes (usually they have only translational freedoms). it is then a problem to join solids with beams.

you can ignore the problem, and the beam will be bending under the shell, as though there's a uni-joint between them.

you can RBE the beams to the solids, which'll weld them together.

you can release the beam bending, so the beam elements will have zero moment at the shell.

another day in paradise, or is paradise one day closer ?
 
I don't use solid and shell elements in this model. My recent thread is already out-of-data.

Plate elements which are part of roof should work independently of frame structure.
Actually I use this plate elements only to transfer area loads on load-bearing structure (wooden frame).

When I release beam bending, then I get rod element but that's not what I want.
 
Hello!,
You can release DOF at ends of beam elements, this is named the PIN FLAG feature, take a look to the CBAR/CBEAM elemenst in the NX NASTRAN manuals to understand how it runs.

cbeam-pin-flag_pruzhw.png


Also, you have an example explained in my web site in the following address (in Spanish, of course -- use GOOGLE Translator):

Best regards,
Blas.

~~~~~~~~~~~~~~~~~~~~~~
Blas Molero Hidalgo
Ingeniero Industrial
Director

IBERISA
48004 BILBAO (SPAIN)
WEB: Blog de FEMAP & NX Nastran:
 
Hi,

To do it with Femap for Bar / Beam elements go to Modify/Update Elements/ Beam/Bar Releases

Seif Eddine Naffoussi, Stress Engineer
33650 Martillac û France
 
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