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re: Vibrating machine

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Question by Ritesh:
 
Hi all,
  
  I have checked that natural frequencies of foundation and of machine are apart by atleast 20 percent. Also, amplitudes have been checked against permissible amplitudes by using Barkan's method.
  
  However, for static analysis of Machine foundations, how the amplification in the dynamic force can be considered with respect to natural frequencies of the foundation and excitation frequencies of the machine.
  
  Please help.
  
  Thanks in advance,
  
  Ritesh
 
REPLY:
 
Assume the machine to be at resonance.
Get the damping ratio. (Site dependent)
Use single-deg-of-freedom formula to get magnification.
Multiply the unbalace force by that magnification.
Sincerely,
Gregory from Oz