The FRFs attached definitely do not look as they should.

[4445]

I am using Labview 8.5, Sound and Vibration 6.0, NI 9233 USB, Triaxial DeltaTron Accelerometer Type 4524, Impact Hammer Type 8206 and cantilever beam to conduct an impact hammer test to obtain FRF solution. As shown in impact waveform attached double impacts or more are present. How can I make sound and vibration use only the first impact and exclude the remaining in obtaining the FRF. The FRFs attached definitely do not look as they should. What are all these peaks present? Kindly note that I have tried to change the rates and number of samples but with no improvement in the FRF. Some noise is present from the accelerometers. May this be the reason for the unexpected FRFs?

[Michael G]

Hi 4445.

I would recommend taking a look at the example "SVA_Impact Test (DAQmx)" which can be found by going to Help -> Open Example -> Sound and Vibration Assistant.  It seems that this example is different in certain versions but there's another forum thread that discusses this example as well.  The link for it is below.  One thing to notice is the use of the "Limit Test" step which may help you filter out double hits.  I hope this helps!

Is there a tutorial on how to set up Signal Express for Impact hammer testing?

Regards,

Michael G