Search the Community
Showing results for tags 'fft'.
Found 4 results
Hi, I create from a curve a FFT. The amplitude of the curve is of 1, but the magnitude of the FFT is a lot lot time higher than the original data. I have observed that it changes according to the number of point data from the original curve. Is a procedure to fix this? or I am missinterpreting something? Thanks
Submitted by Joe on Wed, 10/26/2011 - 18:52 Hi, How can I look at the frequency spectrum of a portion of my data, say from 15 to 60- seconds rather than the full run of 0 to 60 seconds? Thanks, Joe
Hi, I am performing FRF analysis of an overhang part mounted on engine. From testing, I requested following vibration data at mounting and at tip- 1) G vs RPM (sweep up) - from this I got to know at which RPM, G value is maximum due to resonance. 2)FFT data (G vs Freq) at that single RPM where G was maximum while sweep up. Now, my query is ...from FFt data, my maximum G value at particular frequency is less than 1G . But from sweep up data (G vs RPM), if I check G value at that RPM , then it is more than 3G. So, Now For FRF analysis in CAE, which G value I should take for excitation input (from FFT or from sweep up). How to correlate max. displacement and acceleration plotted at tip in CAE with testing. Thanks in advance.
Let's assume that there is a curve f(a, t) in time domain and we apply FFT to the function, assigning values to a (like a=a1, a2, a3, . . . ., an). Then, as a result we can get n FFT curves in frequency domain, F1(a1,f), F2(a2,f), F3(a3,f), . . . , Fn(an,f). We want to plot those FFT curves in a 3D plot which has frequency as x axis, "a" as y axis and FFT magnitude as z axis. Can it be done? Of course yes!!! This is what we get with the enclosed script: fft_3D.oml