Non-stationary random responses of a multi-degree-of-freedom system by the theory of evolutionary spectra

Abstract

General expressions for the closed form transient receptance, evolutionary spectral and cross-spectral densities required in the non-stationary random analysis of structures, discretized by the finite element method, to non-stationary random excitations are presented. Application of the derived results to the non-stationary random analysis of a mast antenna structure subjected to base excitations treated as a uniformly modulated random process is made. The computed results of evolutionary spectral and cross-spectral densities are presented graphically.