Equation for transmissibility estimation
Equation for transmissibility estimation
(OP)
Folks, Anybody have a good equation to estimate the transmissibility of the cylinder along the axis? (In my application, the cylinder is hanging vertically downward). Steinberg used the equation Q = 2 sqrt(fn) in some of his examples to estimate the transmissibility of beam structure. But I suspect the Q is orientation dependent and my not be applicale to my case.
Anywhere I can find of good collection of equation for estimating transmissibility of different structure?
Note; fn is resonance frequency
Thanks.
Anywhere I can find of good collection of equation for estimating transmissibility of different structure?
Note; fn is resonance frequency
Thanks.





RE: Equation for transmissibility estimation
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Equation for transmissibility estimation
The tramissibility (Q) is simple the ratio of maximum output force to the maximum input force on a structure during vibration. At resonance, Q can be very high. Steinberg indicated that the force is proportion to square root of natural frequency of the structure.
Regards,
RE: Equation for transmissibility estimation
Here is a longer answer...
Q is the transmissibility at resonance, preferably for a single-degree-of-freedom system.
Q is related to the damping ratio. The damping must be measured for a given test item including its boundary condition.
Damping cannot be calculated using analytical formulas. Empirical damping formulas are questionable.
Furthermore, the response of a continuous structure or even a multi-degree-of-freedom system depends on eigenvectors, effective modal mass values, modal participations factors, as well as on the modal damping.
Cylinders are surprisingly complicated. A cylinder has two equations of motion, which include both bending and membrane response. These equations do not even include longitudinal or torsional motion.
I have posted a paper at:
h
Tom Irvine
www.vibrationdata.com