measuring the mechanical response using SoundVib Assistant

[jeff_scharpf]

I am trying to measure the response of an object when subjected to a "strike".  I think it's when you tap something, and you measure the response of the object to obtain the resonant frequency.

I have available: NI 9233 module with a PCB triaxial accelerometer. An impacting hammer with a PCB force transducer can't remember the model but it provides mv/LB force.

I am a little confused as to how to approach this problem. I thought that I would put the force transducer on the hammer, put the triaxial accelerometer on the DUT, and hit it.

I'm using Signal Express, Sound and Vibration Assistant, and I have Labview 8.61 with the latest Sound and Vib Suite. To keep it simple I'd prefer to use Signal Express or Sound/Vib assistant.

I set up the program to capture data for one second. I used "Frequency Response" and put the force transducer as the stimulus and the remaining three channels of acceleration as the response.

I'm not sure if what I'm doing is even valid. Can I combine a measurement of force with acceleration in the Frequency Response object?

Does anyone have any tips? As stated earlier, I simply want to measure the resonant frequency of an object by hitting it. I have been told this is a method but I really am having trouble understanding.

Any advice is greatly appreciated.

Jeff

[DFGray]

It is fairly easy to do what you would like to do.  In SignalExpress, set up the 9233 to trigger on an appropriate level of your input signal.  The input should looking like a decaying sinusoid (or could be quite a bit more interesting if you have a lot of harmonics).  Make sure you are taking enough data to get at least ten cycles of your resonant frequency.  If you wish, you can take far more data than you need and use the Subset and Resample step to take out the piece you want.  Use the Power Spectrum step on the output to generate a plot of the resonant frequencies. Use Peak Search on the output of the Power Spectrum to generate a list of the resonant frequencies.

If you want to see a LabVIEW implementation of a similar project, check out this post.

[jeff_scharpf]

 Thanks for the response! I will try your suggestion and read the link.