Connect rigid constraints with beam

General Questions
1

Hello everyone. When I create rigid constraints and want to connect them to beam (via keywords). Bolt connection (similar to RBE2 with beams).
Every rigid constraint has two control nodes, for translation and rotation. Do I need to create two beams? One beam between transformation control nodes and second between rotation nodes?

*Rigid body, Nset=Internal_Selection-1_Rigid_Body-1, Ref node=2017, Rot node=2018
*Rigid body, Nset=Internal_Selection-1_Rigid_Body-2, Ref node=2019, Rot node=2020

*Node
1000000, 0.00000000E+000, 0.00000000E+000, 0.00000000E+000
*ELEMENT,TYPE=B32,ELSET=beam
1000001, 2017, 1000000, 2019

*BEAM SECTION, ELSET=beam, MATERIAL= steel, SECTION=CIRC
10.0 ,
0.0 ,1.0 ,0.0

With *Coupling, *KINEMATIC I can also connect beams to surfaces, but only translational degrees of freedom (1 to 3). Can all degrees of freedom be connected (1-6)?

grafik
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2

You can use *EQUATION to connect the DOFs. It shouldn’t be necessary to duplicate beams. There’s also a ccx documentation example where distributing coupling constraints are used for this purpose: Modeling bolt connection with preloaded beam element - #5 by FEAnalyst

1 Like
3

coupling type kinematic only connect translation dof’s and applicable with imaginary beam element for prestressed load. Quadratic beam element (B32) is not imaginary as previous, rotational dof need to connect by definition in equation relationship. Even these are simple by static equilibrium, input file can be large and cumbersome by manual editing cause number of node in faying surfaces.

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4

If you have a rigid constraint and a beam to connect, you can add the end node of the beam to the node set of the rigid constraint. So you do not need any other connections to the beam.