Finding the natural frequency of a set of data

[agindy86]

Homework Statement

Hi all, I'm having an issue with a homework problem. I'm taking a vibrations class and in our lab we had a cantilever beam with a mass on the end. There is an accelerometer on the beam and we used an impulse hammer to hit the beam. We had software that recorded all the frequency, force and accelerations of the beam while it was vibrating and it was put all into an excel file. From this given data we then have to find the natural frequency of the beam. I am racking my brain trying to figure out how to go about doing this but I'm stumped. Does anyone have any suggestions?

Homework Equations

I know how to find the natural frequency with the given mass and stiffness values but we need to be able to find it using the given data that was recorded during the experiment.

The Attempt at a Solution

This is where I need the help

 

[Redbelly98]

Welcome to PF.

Has your class discussed Fourier Transforms?

And if so, your professor should have made some software available to you for taking the Fourier Transform of your data

 

[nvn]

agindy86: In your output data, look for the maximum peaks of the displacement response magnitude. Obtain the time period between these maximum peaks.

 

[agindy86]

First off, thank you for your help. And no we have not discussed Fourier transforms. I'll look into finding the maximum peaks between time periods. Thanks again