Modal balancing of flexible rotors
Modal balancing of flexible rotors
(OP)
Hello.
I'm studying the modal balancing of flexible rotors and I found a small problem with this technique.
I found strange modelling the rotor as a non-rotating structure, i.e., neglecting the gyroscopic matrix, to find the modal shapes.
So my question is: the mode shape of the rotor at the first critical speed is the same of the first mode shape of the rotor at rest?
Thank you.
I'm studying the modal balancing of flexible rotors and I found a small problem with this technique.
I found strange modelling the rotor as a non-rotating structure, i.e., neglecting the gyroscopic matrix, to find the modal shapes.
So my question is: the mode shape of the rotor at the first critical speed is the same of the first mode shape of the rotor at rest?
Thank you.





RE: Modal balancing of flexible rotors
None the less, it is very easy to predict the whirl speed of shafts by measuring the frequency of their non-rotating bending mode (I only ever need to worry about first mode, luckily).
Cheers
Greg Locock
RE: Modal balancing of flexible rotors
Thank you!
RE: Modal balancing of flexible rotors
Most classical balancing techniques rely on linearity, if only because the system will get more linear as the balance improves.
Cheers
Greg Locock
RE: Modal balancing of flexible rotors
Jason Chen