1 Reply Latest reply on May 16, 2007 7:41 PM by genexxer genexxer

    Rotational Resonant Frequency

    Brian Dempster
      I need to predict the Rotational Resonant Frequency of a round diskmounted to a shaft.
      Setup for Natural Resonant Frequency is straight forward and Idon't have any problems. I have tried fully restraining the shaftand restraining the disk in every direction except rotational.

      The results are many times lower then I would expect. Am I settingup the model correctly, or is there a better way?
        • Rotational Resonant Frequency
          genexxer genexxer
          Classical closed form theory says that its always mass, stiffness, damping and restraints that natural frequency values depend upon. In FEA, the type and number of elements can also have a strong effect. For modes that involve bending, I always use high quality elements. For bending, draft elements don't cut it since the lack of mid side nodes makes the possibility of simulating the curvilinear nature of bending remote. BTW, natural frequency's weaker dependence upon damping isn't simulated by the solver in 2007.