Setting up constraints

Hello everyone, Im a new SimScale user and i need some help setting it up my simulation.

I would like to carry on an FAE analysis on magneto-rehological shock absorber, which consist in a hollow cylinder, containing a piston and MR fluid. For my analysis I would like to fix the bottom end while allowing the piston to move. Can anyone give me any suggestion on how to do that?

Thank you.

Hi @fbezzi1,

Thanks for posting your question and welcome :slight_smile: Do you have a project link you could share so we can see the exact model you are wanting to simulate?

Hi, and thanks for taking the time to reply.
Hi was trying to replicate a project available in the public project section (see link below) to first understand how it is done, since i still don’t have the CAD file assembly to test. I will have to carry on a very similar analysis on my assembly anyways. If could help with that would work as well.

Than you, Fabrizio.

Hey @fbezzi1!

You would not be able to perform a simulation here considering MR fluid. Magnetorheological fluid becomes nearly viscoelastic solid material when subjected to a magnetic field which so far SimScale can’t handle. Though you can do the structural analysis with the piston itself. Do you have any idea how you can proceed without considering this oil?

The simulation you want to replicate is I think different from what you are expecting. This simulation only considers the suspension with a load on it. There is no fluid involved in this case.


Hi, thanks to everyone for the reply!
Concerning the simulation, I’m not interested o simulating the behavior of the MR fluid inside the cylinder. As Ahmed said, I’d rather perform a structural analysis on the piston-cylinder assembly when this is subject to an external load. I can find the the equivalent spring stiffness coefficient and damping coefficient when the shock absorber is under operating condition and I also know that the maximum compressive force it will experience is 600 N. Maybe i can compare my MR dumper to a conventional using same k and c when is under operating condition. If anyone has a better idea please let me know.
Thanks again,


Great! I am looking forward to your simulation. Once you have created one with an uploaded geometry, paste the link to the project here and explain me what you exactly want from the geometry. Then I can have a look and see what we can do there :wink: