Hi
I agree that there is much more to say here, but normally one consider eigenmodes as fundamental entities independently of their way of excitation. When you excite with a sinus you enter the energy in one ray so you excite ideally only 1 mode at the time (or some harmonics). If you enter with an impulse you should do the correlation of the impulse frequency spectrum with the eigenfrequency spectrum. With different damping you then have different decay times (which is another story).
So if you talk about a music instrument you should optimise its design to give you just a few excited notes, and damp any parasitic mode, the its the way you hit tit that will excite more certain rather than other modes
This is then related to a PSD (power spectral density) of an excitation what are all the true hypothesis underlaying that allows us to use a PSD as a representative way to run a frequency sweep to excite "truly" a system. Most engineers forget them quickly (and violate them easily) but you can find books full on signal processing around these issues.
As an engineer I still use and accept a PSD as a good entry for frequency sweeps and analysis of structures, remaining with the issue how to simulate the true damping of a system such to have representative peak heights and energy per mode distributions
--
Good luck
Ivar
I agree that there is much more to say here, but normally one consider eigenmodes as fundamental entities independently of their way of excitation. When you excite with a sinus you enter the energy in one ray so you excite ideally only 1 mode at the time (or some harmonics). If you enter with an impulse you should do the correlation of the impulse frequency spectrum with the eigenfrequency spectrum. With different damping you then have different decay times (which is another story).
So if you talk about a music instrument you should optimise its design to give you just a few excited notes, and damp any parasitic mode, the its the way you hit tit that will excite more certain rather than other modes
This is then related to a PSD (power spectral density) of an excitation what are all the true hypothesis underlaying that allows us to use a PSD as a representative way to run a frequency sweep to excite "truly" a system. Most engineers forget them quickly (and violate them easily) but you can find books full on signal processing around these issues.
As an engineer I still use and accept a PSD as a good entry for frequency sweeps and analysis of structures, remaining with the issue how to simulate the true damping of a system such to have representative peak heights and energy per mode distributions
--
Good luck
Ivar