Non-stationary response of large linear FE models under stochastic loading

A numerical procedure to compute the statistical second moment (variance) characteristics of the response of linear structures––modeled by large FE models––under stochastic loading is presented. For this purpose modal analysis including a static correction procedure is applied in order to calculate the structural response. A non-white, non-zero mean, non-stationary, distributed loading as applied is represented by the well known Karhunen–Loéve expansion, which allows to describe any type of non-white excitation and can be easily adjusted to available statistical data. In the proposed approach, step-by-step integration procedures developed for deterministic FE analysis are applied in order to compute the second moment characteristics of the stochastic response.