what is the difference between RBE2 and RBE3 elements?

Pioneer
Pioneer

Hi

Could someone tell me where should i use RBE2 element and RBE3 Element.Where should i use them.

Please help me understand both of them with an simple example.

6 REPLIES 6
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Re: what is the difference between RBE2 and RBE3 elements?

Siemens Phenom Siemens Phenom
Siemens Phenom

The following comments assume default element dof settings.

 

In a RBE2, grid 1 is the independent and grids 2-n are dependent. The relative position of grids connected by the element does not change during the analysis.

 

In a RBE3, grid 1 is the dependent and grids 2-n are independent. Grids 2-n are free to mode relative to each other. The displacement of grid 1 is the weighted average of the displacements of grids 2-n.

 

RBE2 is used to represent a rigid connection. RBE3 is used for load distribution or a flexible connection.

 

See R-Type Elements in the Element Library Reference in the online help.

 

Re: what is the difference between RBE2 and RBE3 elements?

Solution Partner Phenom Solution Partner Phenom
Solution Partner Phenom

Hello!,

To learn more about RBE2 vs. RBE3 elements take a look to my blog in the following address:

https://iberisa.wordpress.com/2015/10/13/rbe2-vs-rbe3-on-femap-with-nx-nastran/

Best regards,
Blas.

Blas Molero Hidalgo, Ingeniero Industrial, Director
IBERISA • 48004 BILBAO (SPAIN)
WEB: http://www.iberisa.com
Blog Femap-NX Nastran: http://iberisa.wordpress.com/

Re: what is the difference between RBE2 and RBE3 elements?

Creator
Creator

Hello Blas!

 

Is there any source in English?

Re: what is the difference between RBE2 and RBE3 elements?

Gears Phenom Gears Phenom
Gears Phenom

Here is good MSC Nastran slides that describe RBE stuff.

https://www.slideserve.com/deanne/rbes-and-mpcs-in-msc-nastran

Re: what is the difference between RBE2 and RBE3 elements?

Creator
Creator

Thank you Karachun! Smiley Happy
I am calculating the deflections of a component that is turned on Lathe. I have the cutting forces acting on each point of the component. Since these are point loads, is it correct to use RBE3? 
If yes, could you please tell me where to define the point of load? (shall it be the central axis or the point where the cutting tool meets the component)?


Re: what is the difference between RBE2 and RBE3 elements?

Gears Phenom Gears Phenom
Gears Phenom

Attaching example file (in .dat/.bdf formad) will be good.