So how would YOU measure the mechanical impedance of a structure? Is it just the real and imaginary part of a transfer function? I still don't know how to measure mechanical impedance... doug > -----Original Message----- > From: Stephen Birkett [SMTP:birketts@wright.aps.uoguelph.ca] > Sent: Tuesday, December 29, 1998 9:02 PM > To: pianotech@ptg.org > Subject: impedance (was negative crown_ > > Del wrote: > > > Ah, but Doug, the idea of mechanical impedance, or wave impedance, is > > very important if one is to understand the function of a vibrating body > > such as the piano soundboard. It is a function of the square root of > the > > inertia times > > > To Systems people impedance is a concept that can be applied in all > physical domains, including multi-domain systems for which it it > especially useful. > > Don't forget that impedance is a complex number - the usual intuitive > "definition" (above) is the magnitude of that complex number only. The > time behaviour - lead and lag- comes from the relative size of the real > and imaginary parts of the impedance. > > Stpehen > > Stephen Birkett Fortepianos > Authentic Reproductions of 18th and 19th Century Pianos > Waterloo, Ontario > Canada N2T 1K5 > tel: 519-885-2228 > email: birketts@wright.aps.uoguelph.ca
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