Anyone has used ansys to simulate bearing in dynamic condition?

[mrjamsbond]

Hi, is there anyone has tried use ansys to simulate a bearing? I met converge problem and hope somebody can help me. Thanks.

 

[rickfischer51]

Your post is way to vague. You need to actually describe what you did and what happened.

Rick Fischer
Principal Engineer
Argonne National Laboratory

 

[mrjamsbond]

Hi Rick,

I found it is really hard to set the contact between ball and cage,inner race,outer race. I set the contact between ball and cage is frictionless.The interface treatment is "add offset and ramp effect". The contact between ball and ring is frictional with a small frictional coefficient. Treatment is "adjust to touch".These nonlinear contact can bring a lot problems. I do a modal analysis and cage flies out. Do you have ideas to solve it? Thanks.

 

[rickfischer51]

I don't think you can do a modal analysis in Ansys on a nonlinear model. The cage flies out because the nonlinear contact elements are not recognized by the linear modal solution, so the cage is unattached. I'll bet you have a lot of zero frequency modes. I think the usual way to do modal on an assembly containing a bearing is to model the stiffness and damping with a dampened spring. Workbench has a bearing element that does that. Search the Mechanical Applications Manual in help for bearing.

Rick Fischer
Principal Engineer
Argonne National Laboratory

 

[loki3000]

search for other scientific papers, you are not the first with that task.

 

[mrjamsbond]

I have searched for a long time. But I didn't find any papers that have done a modal analysis for a bearing(or rotor-bearing system) in ansys workbench.Can you show me one?Thanks.

 

[rickfischer51]

You're not trying very hard. I found these in the first ten hits on a google search for "rotordynamics ansys"

http://www.mecheng.osu.edu/documentation/Fluent14.5/145/ans_rot.pdf

https://www.civ.cvut.cz/.../ansys.../RotorDynamics/rotordynamics_80.pdf

http://www.ansys.com/.../AA-V4-I2-Turning-to-Rotordynamics.pdf

http://www.ewp.rpi.edu/hartford/~ernesto/.../Trebuna2011-RD-Ansys.pdf

http://www.scribd.com/doc/33750426/Rotor-Dynamics-With-ANSYS-Mechanical-Solutions

Also, RTFM, as they say. There are sections on rotordynamics in the Mechanical Applications manual and the Mechanical APDL Manual, and a Workbench verification problem at VMMECH087.

Rick Fischer
Principal Engineer
Argonne National Laboratory