Same rotation

[Kiwing]

Hi,

I am trying to enforce that two beams have the same rotation at the end surfaces. The rotation is caused by the displacement of the same surface.

My first idea was to use *kinematic coupling, displacing the referene points at the end surface as required and using an *equation to couple the rotation of the reference points (complete input file is attached).

*Coupling, CONSTRAINT NAME=KINEMCOUPTop1,
           REF NODE=TopRPSet1,
           SURFACE=TopSURF1
*Kinematic
1, 6
*Coupling, CONSTRAINT NAME=KINEMCOUPTop2,
           REF NODE=TopRPSet2,
           SURFACE=TopSURF2
*Kinematic
1, 6
(...)

*Equation
3
TopRPSet1, 4, 1, TopRPSet2, 4, 1
(...)

*Boundary
TopRPSet1, 2, 2, 0.5
TopRPSet1, 3, 3, 0.5
TopRPSet2, 3, 3, -0.5

This approach doesn't work, as apparently the reference point in *kinematic coupling doesn't rotate with the corresponding surface (only the rotation of the surface follows the reference point, not vice versa).

Is there another way to achieve this goal?
(For instance using *MPC or using a different node definition?)
Or is there a mistake in the input file and this can indeed be done using *kinematic coupling?

Kind regards
Marco

 

[Mustaine3]

Number of terms = 3 ?
And shouldn't be there a -1 at the second line of the equation?