This paper discusses the random response of a non-linear Duffing oscillator
subjected to a periodic excitation with random phase modulation. Effects o
f uncertainty in the periodic excitation and level of the system non-linear
ity on the response moments and non-Gaussian nature of the response caused
by both the system non-linearity and the non-Gaussian loading are investiga
ted. Results are presented in terms of the second- and the fourth-order mom
ents as well as the excess factor of the response and some results are comp
ared with those from the Monte Carlo simulation. An iterated linearisation
technique is proposed to improve the accuracy of the numerical results for
strongly nonlinear systems. (C) 1998 Published by Elsevier Science Ltd. All
rights reserved.