For most vibration testing people use calibrated accelerometers and frequency analysers to verify frequency and amplitude. Other option is to acquire acceleration time histories and post process in Matlab (FFT analysis).

we are using vibrometer VIB-40 model for calibration of vibraters(9000rpm) while casting prestressed concrete sleepers bench. It was performing well for details go through (http://www.mcminstruments.com/vibrometer-vib-40-139705.html)

You can run a white noise vibration and use a calibrated accelerometer to measure the response. Then use FFT to obtain the frequencies.

Thanks all

Providing these useful method for me, however, how do I program FFT by means of Matlab to acquire the frequency of the vibrating table? Anyone have other details about Matlab to deal with it.  

hey Chiahung,

The easiest method to get the natural frequencies from a system is to use the Operational Modal Analysis (OMA).

The company bruel&kjaer (see link below) provides software that will allow you to transform the data measures by your accelerometers into a frequency response graph and will also show you how your structure behaves when reaching a mode shape.

You can see a previous work where the OMA is applied.

https://www.researchgate.net/publication/287995420_Mode_Shapes_Investigation_on_a_Steel_Structure

Regards

http://www.bksv.com/Products/analysis-software/vibration/structural-dynamics/operational-modal-analysis.aspx

Research Mode Shapes Investigation on a Steel Structure

Hi Arnaud

thanks your help, I look up on the website, it couldn't provide the free sofeware to download or trial edition. I have to try to program FFT by Matlab or other options to deal with it.    

Good question.. Please share me the best answer might you trust...

Regards…