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Is it allowed to expand a RBE2/RBE3-connection to a second RBE3 element?

Gears Phenom Gears Phenom
Gears Phenom

Hello experts,

 

after connecting shell elements  with edge to face connections (RBE2/RBE3-spider connections) I must realize that the projected grid point line of RBE2 elements hit exactly  a grid point line of the target area. Therefore, the RBE3-spider elements are placed :

- only on one side of the shell elements of source area or

- in a mixed manner on both sides of the shell elements of source area or

- only in disconnected manner at target elements.

 

See here:

2018-11-16_164738.png

 

 Sometimes the target mesh can't be modified to get a centered target element for RBE3-spider to have a suitable meshed connection.

 

Therefore my question:

Is it allowed to create a second or maybe more than one RBE3-elements connected with the center node of RBE2 element to widen the target area?  Or asked in another way,  does a RBE3-spider element has to operate here strictly with only ONE target shell element or could the leg nodes also deal with more than one element?

 

Who can help? Best wishes, Michael

| Production: NX10; Development: VB, TCL/TK, FORTRAN; Testing: NX11 | engelke engineering art GmbH, Germany
| Kudos for good posts! And if my post answers your question, please mark it as an "Accepted Solution".

2 REPLIES

Re: Is it allowed to expand a RBE2/RBE3-connection to a second RBE3 element?

Gears Phenom Gears Phenom
Gears Phenom

RBE3 is simply an MPC. So you can attach as many nodes you want - anywehre in the model (ignoring possible double dependency). it means that the "dependant" node will be have an "average" response of all the "indepedant" nodes.

 

Might get "ugly" and may not do what you really want/have in mind!

 

Mixing RBE2& RBE3 might not be a good idea. By centre node you mean the indepdant node (some call it the master node).

 

 

When attempting what you picture is showing, I would try on a very simple model, with say a simple tensile load to undersantd how the forces are going though this "mixed" approach.

Production: NX.CAE 9.0.3.4, NX.CAE 10.0.2.6
Development: VB.NET (amateur level !)

Re: Is it allowed to expand a RBE2/RBE3-connection to a second RBE3 element?

Siemens Phenom Siemens Phenom
Siemens Phenom

I would recommend edge-face gluing over the rbe2/rbe3 connection shown here.