FFT of vibrations analysis

Hello,

I need to find the resonant frequencies of data that was taken from a vibrations experiment. I have 3 vectors as time, displacement, and force where:

time(16384,1) is sampled time

displacement(16384,1) is sampled displacement

force(16384,1) is sampled force

I need to calculate and plot the magnitude of the displacement-force transfer function with frequency from 0 to 30 Hz. My sampling frequency is 100 that I was able to calculate from the data. I was able to find another question that was similar to this but I couldn't get my output quite right any help would be great.

Answer 1

[Image Analyst]

Did you try the fft() and plot functions, or not? I assume you did because you mention FFT in the subject line, so you're not just asking which functions to use. Actually you didn't even explicitly ask any question at all , so please ask one. Please attach your m-file.

[Image Analyst]

Why do you think that it's supposed to look like figure 2?

Answer 2

[Zack]

My basic code that I have is attached and figure1 is what I currently am getting as an output but I need it to look like figure2.