Solid bending problem

[fisken90]

Hi Guys!

I'm trying to bend a pipe in Abaqus. I following this video:

https://www.youtube.com/watch?v=soYwaW54WRg

on my model in the picture attached. I'm using the block on top to bend the pipe underneath. The job runs and completes but nothing happens and I have the following error messages:



MPCS (EXTERNAL or INTERNAL, including those generated from rigid body definitions), KINEMATIC COUPLINGS, AND/OR EQUATIONS WILL ACTIVATE ADDITIONAL DEGREES OF FREEDOM

Output request rm1 is not valid since it requests output at a dof that is not active

Output request rm2 is not valid since it requests output at a dof that is not active

Output request rm3 is not valid since it requests output at a dof that is not active

Output request ur1 is not valid since it requests output at a dof that is not active

Output request ur2 is not valid since it requests output at a dof that is not active

Output request ur3 is not valid since it requests output at a dof that is not active

Boundary conditions are specified on inactive dof of 3 nodes. The nodes have been identified in node set WarnNodeBCInactiveDof.

There are 2 unconnected regions in the model.



Any tips or do I need to provide more information?

Thanks in advance!

 

[Dave442]

From your image it looks like there is no contact between the pipe and the block. Did you set up an interaction? Are your interaction properties correct? Are your surface definitions correct? Are your instances orientated correctly?

 

[Mustaine3]

Just watched that video. There are a couple of bad definitions in there. And with that mesh and probably wrong element type, I think also the results are wrong.

I just can't understand, why people with no real understanding of Abaqus think they have to do a tutorial video...

 

[Dave442]

There is an example of a three point bend test in the Abaqus Example Problems Guide:

2.1.16 Progressive failure analysis of a thin-wall aluminium extrusion under quasi static and dynamic loads

Although it is not a static analysis and also includes damage and failure, it might help you figure out your boundary conditions, interactions etc..

 

[fisken90]

I did it with rigid shell elements instead. This worked much better, but I still have a few problems. With a solid cylinder the job runs but the first few steps of the visualization, the parts shifts acoording to eachother, I attached a picture. When I run a model with a hollow cylinder, I get the the warning: There is zero FORCE everywhere in the model based on the default criterion. please check the value of the average FORCE during the current iteration to verify that the FORCE is small enough to be treated as zero. if not, please use the solution controls to reset the criterion for zero FORCE.


Any ideas?

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