Constraining motion of two rigid bodies in contact with a deformable

[hnng]

Hi All,

I am trying to constraint the motion of two rigid bodies such that the horizontal (U1) velocity components are the same. I am using abaqus Explicit solver.

First I tried with two analytical rigid triangle and used the top vertices as the reference point and used COUPLING-kinematic constraint and gave initial velocity in U1 direction to one of the triangle reference point. In the results I saw everything is working as expected both the rigid bodies attains the same velocity in U1 direction.



Now I tried to put a beam on which these two rigid bodies will be moving and defined a contact between the rigid triangle's exterior surface (whose horizontal part is in contact with the beam surface) and defined the same coupling-kinematic constraint as above it does not work. The rigid body on which the initial velocity is applied goes out as expected but the other rigid body does not move.

When I go to visualization and try to animate the time history I get the following message in a popup box
"Results for the current deformed variable are not available for one or more nodes contained in the model. Deformation at such nodes are assumed to be zero."

In the History output request I have requested the output for the rigid body reference points on every 2nd increment. I am attaching a snap shot from abaqus view port for illustration of the problem setup.

Can some one help me on how to make this case work.

Regards

 

[hnng]

Hi All,

I left a important thing in the writeup, there is a concentrated downwards vertical force acting on the reference points of the rigid triangle. Which applied in the first and only dynamic,explicit step.

Regards

 

[bassmanjax]

I wouldn't bother with the coupling constraint between the two ref points - just apply the x velocity to both nodes;

*boundary, type=velocity, amplitude=Velocity_Curve
ref_point_1,1,1,5
ref_point_2,1,1,5

Makes life a bit simpler. I'm not sure what the popup error in Viewer is about though.


Martin Stokes CEng MIMechE