[sdiy] Are power electrolytics microphonic?

[Toby Paddock]

Semi-OT:
I'm doing vibration testing on some fairly large (but not real large) 
electrolytic caps. And I was wondering if I could find the resonant 
frequency of the guts by charging it up thru a high resistance and 
looking for an AC signal when the stuff starts flexing inside. 
(That sentence was way too long.)

Seems like if the layers flex and move, it might change the 
capacitance. So with a constant charge, that would vary 
the voltage.

They are like 450 WVDC and I don't know the C value. The 
aluminum can is about 1.25 inch dia. by 3.5 inches long.

Ideas? Opinions? Advice? Point and laugh?

Thanks,
 - -- -  Toby Paddock