Evaluation of Vibration References with Equivalent Kurtosis and Dissimilar Amplitude Probability Densities

The generation of Gaussian noise with a specific auto spectral density (ASD) is a well-documented process employed in drive signal generation in vibration control applications. In recent years, vibration control system vendors have introduced the ability to modify the probability density function (PDF) characteristics associated with the reference ASD, yielding a non-Gaussian drive. The specific parameter defining this process is kurtosis. This paper will discuss concerns with this practice in terms of synthesizing a time history with dissimilar PDF characteristics to that of the measured data upon which the original ASD and kurtosis characteristics were based. An example is discussed from both statistical and fatigue perspectives.