Viscoelastic damper with rotation

[mamj]

Hi,

I'm working on a research problem that involves a mechanically interlocked viscoelastic damper. In the experiment I connected the the damper to the universal testing machine using brackets that are bolted to the damper and the machine. because of the interlocking nature of the device the flanges where moving outwards in a rigid body motion because the forces where not completely vertical on the bolts + the bolts where not tightened with enough pre-tensioning force. I can simulate the behavior by using a pin connection as shown in the attached image but the issue is that it doesn't offer any resistance in the lateral direction that is offered experimentally by the bracket. I'm trying to use a spring element but it's not working.

Any ideas on how I can solve this problem?
Thanks!

 

[FEA way]

Connector elements should let you achieve this goal. But it would be best if you could attach an image showing the test rig so that we have a full picture of how it works in real life.

 

[FEA way]

What may help is to model a larger piece of the test rig. Especially that the analysis is performed in 2D and such change shouldn’t increase the calculation time too much. A more complex (but still simplified) model of the system, with an appropriate representation of the bolted connections (there are several possible approaches), should yield better results by ensuring the correct stiffness of the test device in both directions.

 

[mamj]

What are the different approaches? I know that I can use MPC or connector elements. Do you recommend a certain approach?

 

[FEA way]

Check the article titled "Modeling Bolted Connections with Abaqus FEA" on Simuleon's blog. It shows different bolt modeling techniques for use in Abaqus, including solid and 1D representations. You can start for example with beam elements and beam type MPC. If it doesn't give you the expected results, try other options.

 

[mamj]

Thank you!