Torsional Analysis

[VibFrank]

Hy,
I try for the first time to do a torsional analysis of a shaft configuration with a hydrodynamic coupling. I have the frequency-dependent stiffness and values of the coupling.
some questions:
How do you model such a coupling ? tors-spring with damper ?
Which stiffness-value do I take for determining the mode-frequencies ?
Which stiffness-value do I take for the transient analysis of the different motor-situations (short cirquit, start...).

Thanks a lot for your comments

 

[VibraSense]

I might be too late but did you try DyRoBeeS software.

http://www.dyrobes.com/index.htm

I am using this software for last 15 years and I had great success in analyzing the branched systems. It is simple and acurate.