Search results for query: *

Hello, I was wondering if it is possible to change a mobility measured FRF to a receptance FRF so I can take advantage of the program I developed to recontruct receptance FRF with a rational fraction method. I thought maybe just simply dividing the Mobility matrix by iω? Thank you

Thanks a lot for the reply, now i see clearly what you meant. Could you link me the file of that circle fit Greg? I went with a least square approach to reconstruct the FRF (with success, getting all 4 peaks i selected very well, just missing the complex mode shapes) and i would like to learn...

And if you need it here is the frequency vector for this particular case.http://files.engineering.com/getfile.aspx?folder=7f868c5c-1a32-4ce7-b154-290fb145a558&file=f.mat

Here goes 21 FRF corresponding to 21 points of measurement (driving point is the first column).http://files.engineering.com/getfile.aspx?folder=47b96280-1533-44b6-9452-2c1350f7c988&file=H.mat

Okey, so let's see if i got the idea. What i understand that i have to do by seeing the circle fitting, is to get the values of the FRF (both real and imaginary part) for the natural frequencies, and for each one the phase of the mode shape is the tangent arc of the imag(FRF)/real(FRF). Is that...

Thank you for the reply Greg, but i have already done that step. I have natural frequencies, modal constant and damping of each mode. I plot the reconstructed FRF and matches very well from the ones i measured. My problem is obtaining the complex modes after having this done.

Okey so i managed to get some achievements on this. I extract the modal parameter, which is the product of 2 elements of the modal matrix, and knowing whats my driving point i manage to reescalate all the other mode shapes elements. The problem im having now is that, for viscous damping, these...

But i was wondering if there is any good document that explains step by step what you need to take to reconstruct the mode shapes. Because in many sites its explained in a way that does not give insight of how you should program it in something like MATLAB and i dont really know what to do in...

Hello, Recently i have been tasked to do the modal analysis of the data collected from a test. I was able to obtain its natural frequencies, damping coefficients(viscous and structural) and the modal constant using a SDOF descomposition of the FRF. I am supposed to obtain 4 mode shapes ( since...