The objectives of this project are: to develop reliable schemes for the truncation of the differential equations governing the moments of general systems under nonwhite parametric excitation; to develop appropriate filters for the case of nonwhite excitation; to use the above results to study the response of simple nonlinear and hysteretic structures under nonwhite parametric loads; and to study the response of complex nonlinear systems under nonstationary, nonwhite parametric excitation due to earthquakes, wind and wave forces. Simple structures such as beams will be examined first, and then the methods will be applied to complex systems such as bridges and offshore platforms. This research will result in a much better understanding of the behavior of nonlinear structures subjected to random parametric excitations. The systems will be modeled realistically as nonlinear or hysteretic, whereas the loads will be nonstationary nonwhite processes.
