Shaker manufacturers rate their shakers’ random testing capabilities based on Gaussian distribution, where the kurtosis value equals 3. However, real-world vibration is not always Gaussian. A better method is to adjust the data distribution to reflect the field environment, which involves the adjustment of kurtosis. Test engineers can increase kurtosis values with Vibration Research’s Kurtosion® software to better account for peak acceleration levels.
However, increasing the kurtosis value on a shaker for specific tests may decrease the manufacturer’s random lb-f rating. Engineers can use the relationship between kurtosis and the crest factor to calculate the shaker capacity for a random Kurtosion test. They can determine the crest factor based on the desired kurtosis value and the shaker (de-)rating based on the crest factor.
The Kurtosion shaker capacity calculator provided by Vibration Research will help answer:
- What is the maximum kurtosis capacity of my existing shaker system for my test(s)? How much must I de-rate my shaker for a higher kurtosis value in my test(s)?
- What size (lb-f) shaker is required to run a specific random Kurtosion test?