Kinematic Coupling Problem

[Techsan123]

I am trying to apply rotation to one face of a cylinder. I am familiar with the kinematic coupling feature and can set a ref point as a control point and set the face of the cylinder as the constrained region (either as a node or surface works). I then apply rotation to the reference point as a Boundary Condition (my axial direction along the cylinder is in the X so I apply BC as UR1). This works fine if there is no pressure involved but I am having the following problem when I first apply internal pressure.

In order for the rotation to work I have to constrain all DOF’s in the kinematic coupling feature or else the rotation will not occur even though the step completes. Because of this, the edge of the cylinder which has the kinematic coupling stays the same diameter and will not inflate with the rest of the cylinder.

One would think that the only constraint that would be needed would be to the UR1 rotation direction but the step aborts if I try it this way. I have tried several combos and the only way rotation occurs is if all the DOF are constrained U123 and UR123.

Is there any way to get around this? Maybe use a tie constraint? I am using a 3D deformable solid model. Any help is greatly appreciated!!!

 

[rstupplebeen]

My guess is that with the reduced DOFs on the coupling that you have a rigid body motion. Try adding some constraints like pinning a node on the axis of rotation. I hope this helps.

Rob Stupplebeen

 

[Techsan123]

I'm not sure if that is what it is but I think I need to use connectors instead of a kinematic coupling...Any idea as to what is the best way to approach this?

 

[dezsit]

Hello,

Try to use a cylindrical coordinate system for the definiton of the kinematical coupling.
Set free the U1 translation DOF in this coordsystem, which is the radial motion in this case. So inflation of the diameter can work, and the rotation will be transferd by the translation in tangential direction.

I hope , I understood well your problem, and this helps.