Abstract
Mathematical model of nonstationary random excitation is, in many cases for convenience' sake, expressed by the product of a stationary random excitation and an amplitude modulating function. In those cases, spectral content of modulated excitation may differ notably from that of unmodulated. Therefore, amplitude modulation method doesn't seem suitable for the nonstationary random vibration analysis, in which the frequency characteristic of an excitation is taken into serious consideration. In this study, it is verified that the intensity distribution of a nonstationary excitation is dependent on the phase inclination of that excitation. By making use of the probability characteristics of phase inclination, mean and mean square as well as auto-correlation functions of nonstationary random excitation are derived in the explicit form and are applied to the random vibration analysis of SDF linear oscilator.
