How to measure the frequency of flow-induced vibrations of a strap

[meystingray]

I need to measure the frequency of airflow-induced vibrations in a cloth strap. Can it be determined theoretically? All I know is the length, width, and tension on the strap. I would also like to be able to measure the amplitude of these vibrations. Could I use some sort of photo-diode/laser method? Thanks in advance!

 

[pja]

You can calculate the flutter frequency of the strap using beam(or string) equations coupled to a simple flow model..however the details are too complicated to
go into here. I have seen papers on "paper" flutter and I am doing a calc on flag flutter so it's doable. For the paper flutter study look for the author Watanabe,Y in the Journal of Fluids and Structures. This of course is
for self induced vibrations. Things are a little different
is the vibration is a forced vibration such as buffeting.