A NONSTATIONARY STOCHASTIC-MODEL FOR PERIODIC EXCITATION WITH RANDOM-PHASE MODULATION

The paper presents a non-stationary stochastic model for periodic exci tation with random phase modulation, where the phase modulation is mod eled as a modulated stationary. Gaussian process. Applications of the model are demonstrated by analysis of response of a single-degree-of-f reedom (SDOF) system under such an excitation. The response is, in gen eral, non-Gaussian. Cases of step, rectangular, and exponential envelo pes are considered in the present study. The nonstationary second and fourth order moments are calculated by numerically solving the transie nt moment equations. Non-Gaussianity of the response is studied in ter ms of the non-stationary excess factor. Some numerical results are pre sented. The influences of system parameters, build-up and decay rates as well as duration of random phase modulation on the moment response of the SDOF system are discussed.