COMSOL example model results do not match with Mathematical Model

  1. Hi! I started to look into freq response analysis of a cantilever beam using COMSOL. Luckily COMSOL already has an example model "Model Library>> Structural mechanics module>>Dynamics and Vibrations>>rotating blade". While not changing anything in the model and with Omega=0 and Cloris =0, I get the following results

    Resonance Freq1 = 84.36
    Resonance Freq2 =528.84
    Resonance Freq3 =949.31

    Resonance Freq4 =1316.00
    Resonance Freq5 =1481.41
    Resonance Freq6 =2882.00

    But Euler beam theory (options>>constants) gives me the following

    Resonance Freq1 = 84.36
    Resonance Freq2 =528.66
    Resonance Freq3 =1862.89

    Resonance Freq4 =3650.55
    Resonance Freq5 =6034.61
    Resonance Freq6 =9064.89

    Clearly the results do not match after 2nd natural/ resonance freq. I am quite sure that COMSOL example model cannot be wrong but there is something odd. Some elaboration would be appreciated
     
  2. jcsd
  3. Mech_Engineer

    Mech_Engineer 2,299
    Science Advisor
    Gold Member

    You're wanting to solve a cantilever beam modal analysis, but used a rotating blade vibration analysis. How are the boundary conditions defined?
     
Know someone interested in this topic? Share this thead via email, Google+, Twitter, or Facebook

Have something to add?