Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

COMSOL example model results do not match with Mathematical Model

  1. Jun 12, 2011 #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. Jun 13, 2011 #2

    Mech_Engineer

    User Avatar
    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 thread via Reddit, Google+, Twitter, or Facebook

Have something to add?