mode indicator function

[mhisham1989]

what is the prime difference between mode indicator function and power spectrum of mode indicator function ?
from certain experimental data obtained through impact testing, i could see that there is a variation between the modes indicated by both these methods... why is that happening???

 

[GregLocock]

Off the top of my head I can think of 4 different mode indicator functions, so you need to specify what you are talking about.

I suspect your question actually is

Why does the spectrum of the ratio of imaginary to real, summed over the whole model, indicate different peak frequencies to the power spectrum of the whole model?

The answer is of course that they are measuring different things.



Cheers

Greg Locock


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