Modal Analysis of press fit shaft hub assembly

[h__]

Hello All,

for my master project i need to do Modal analysis of press fiit shaft hub connection to find natural frequencies. I have used friction free contact for the press fit simulation.

1. I found that the differnce between calculated contact pressure and simulated contact pressure is large

2. As the contact interfaces in Modal analysis are ignored, i am trying to idealize the press fit interface by spring, But can anyone please explain how may i calculate the stiffness of spring for press fit interface, or is there any other method to perform modal analysis for press fit.

I ghave attached the CAD files and mathcad calculation in the folder. Any suggestions would be appreciated.

[skunks]

Modal analysis is linear but contact problem is nonlinear.
Your CAD data is created with a training version, better STEP

[h__]

Hello, could you please tell how may i linearize it with springs. 

i have only access to training version, doe it cause any differnce in the results.?

[h__]

also when i am doing the static analysis with friction free interface there is deviation in contact pressure compared to calculated solution. Could you please tell what is reason behind the deviation in contact pressure.

[skunks]

I could look at the problem,
but I need STEP data.

[h__]

Hii,

i have attched the presentation which has detail explaination about the contraints for both modal and static analysis. 

[skunks]

first model attached

[h__]

Hii,

thanks for your feedback, but is there any reason for deviation in mathematical calculation and Fem results about contact pressure..

In this case, which contact pressure is more accurate. Mathematical calculations or Fem results

[skunks · Accepted solution]

there is no deviation, the results are the same

[h__]

Hii,

many thanks for your feedback. This maximum stress concentration (in red color), should i consider it as singularity affect ??

should i neglect the stress at hub edges in red ?

[skunks]

No, no, my model has notch relief,
the stresses are real.

[skunks]

attached is an example of shaft / modal analysis