Hello Raghabendra,

If your dealing with a linear system, you can look at the amplitude of the response versus the forcing frequency, and find the frequency for which you have a peak in your response, i.e. resonance peak.

At the resonance frequency you will also observe a phase shift of 90deg between the forcing and the response: the two signals go from being in phase (phase=0deg for forcing frequencies well below the resonance) to being in anti-phase (phase=180deg for forcing frequencies well above the resonance).

Looking for the frequency at which you have a phase=90deg is a criterion that can be used also for nonlinear system or for highly damped systems, when identifying a resonance peak in the amplitude might not be trivial.

Hope this helps.

Best,

G.

Dear Raghabendra, try plotting vibration amplitudes vs vibration frequencies; if you have a strong peak for a frequency value fN, then fN is a natural frequency, otherwise you have to change your range of vibration frequencies (more high or more small range).

Gianluca

Hello Raghabendra,

If your dealing with a linear system, you can look at the amplitude of the response versus the forcing frequency, and find the frequency for which you have a peak in your response, i.e. resonance peak.

At the resonance frequency you will also observe a phase shift of 90deg between the forcing and the response: the two signals go from being in phase (phase=0deg for forcing frequencies well below the resonance) to being in anti-phase (phase=180deg for forcing frequencies well above the resonance).

Looking for the frequency at which you have a phase=90deg is a criterion that can be used also for nonlinear system or for highly damped systems, when identifying a resonance peak in the amplitude might not be trivial.

Hope this helps.

Best,

G.