It's amazing.
There is a super easy criterion to know whether that can be useful.
How many points can be plotted in a frequency range (Delta F) where Delta F is -3 dB frequency band around a peak ?
Does this number depend on the peak frequency ?
Does this number depend on sampling time (Delta...
I have got the second edition of the book.
The chapter 30 is "Theory of vibration isolation" and the equation is in the section "Rigidly connected coulomb damper"
Hi IRstuff,
It's funny to read your sentense "Sounds like you should be talking to the manufacturer" for a non-native English speakers as me.
You use the words "sounds" and "talking" (reminiscent of crosstalk) to say something which has nothing to do with sound and crosstalk.
Freud would tell...
Wow, it's a subtle question.
Suppose that Ai are the experimental mode shapes (a set of vector). Their amplitude can be very low. So the modal masses can also be very low. This is not good.
When modal mass is normalized, something doesn't change : the Eigen frequency .
Because an Eigen...
Why do you say that acoustic pressure is proportional to the plate displacement ?
Plate Velocity = j * omega * Displacement
From Acoustic point of view, Air Velocity is proportional to Delta Pressure / Delta X.
Since there is equality between Acoustic Velocity and plate Velocity, we get that ...
What is the main difference between normal and complex modes ? The way the phase is taken into account.
With normal modes, the phase exists, but it doesn't matter. Why ? Because the phase is either 0° or 180°. So the amplitude of the mode at each point is given by +something (0°) or -something...
When complex values appear, it means that damping is taken into account.
Imaginary part of a complex eigenfrequency is related to damping value (damping loss factor).
Imaginary part of a complex eigenvector means that mode is not normal (mode is not a stationary wave).
Let's take an example.
Let's suppose a beam, simply supported, length = L, etc..
Let's consider the 3 first modes (N=3)
The modal response is something like this :
P(x) = A1*sin(pi*x/L) + A2*sin(pi*2*x/L) + A3*sin(pi*3*x/L). (Sum of the 3 modes)
You can imagine P(x) (for all x) as just 1 point...
You're not a gentleman.
When you write some lousy messages, I say to myself : " This guy is just an idiot" but I don't write it to the entire community.
