Vibration Research Corporation

Below is a 3 minute video explanation of kurtosion. Click the image below to launch the movie in a new window.

Control the Kurtosis in your random waveform
Our latest innovation in random testing is a novel method of Kurtosis Control (patent pending).
KurtosionTM defined
The action or process of controlling a signal in which the kurtosis of the signal achieves a desired result; as in applying kurtosis.
More realistic probability distributions
By controlling both the RMS and Kurtosis of the random waveform, you get more control over the probability distribution, allowing a closer match between the real world and your test lab.
Not Gaussian
Random Control traditionally uses a Gaussian distribution, which is highly concentrated near the mean value. But the mean value is zero! This means most of the time the traditional random test acceleration is close to zero. In most real world environments there is significantly more time spent at the peak levels than is produced by the traditional random test.
More time at peak levels
When the Kurtosis of the signal is increased, the time spent at the peak levels is increased, making your test better reflect what is happening in the real world. Some have called this "Shock on Random", but it is really Random with a more realistic probability distribution.
Full Random Spectrum
The spectrum is defined and fully controlled just like in traditional random tests.
Full Dynamic Range
The Kurtosis of the acceleration is controlled without any reduction in dynamic range.

VRC KurtosionTM Article in Test Engineering & Management Magazine
(Special Thanks to Test magazine)
"Kurtosis-the missing dashboard knob" by John Van Baren (as PDF)

VRC KurtosionTM Article in Sound & Vibration Magazine (see www.sandv.com, "downloads" tab, "back issues" tab)
(Special Thanks to Sound and Vibration magazine)
"The Missing Knob on Your Random Vibration Controller" by Philip Van Baren (as PDF)

"Limitations of the Fourier Transform for Describing Test Course Profiles" by Alexander Steinwolf and William H Connon III (as PDF)
"Generating Non-Gaussian Vibration for Testing Purposes" by David O. Smallwood (as PDF)

For the following articles relating to "The Missing Knob on your Random Vibration Controller" by Philip Van Baren, please visit the IEST online publications store:
Connon, W.H., "Comments on Kurtosis of Military Vehicle Vibration Data", Journal of the Institute of Environmental Sciences, September/October 1991, pp. 38-41.
Steinwolf, A., "Shaker Simulation of Random Vibration with a High Kurtosis Value," Journal of the Institute of Environmental Sciences, May/June 1997, pp. 33-43.