Dynamic design of structures under random excitation

Abstract

An optimum design method to minimize the weight of a linear elastic structural system subjected to random excitations is presented. It is focused on the constraints of the first passage failure and displacement response mean square (RMS) at certain degree of freedoms. Constraints on natural frequencies and bounds of design variables are also considered in the optimization. Both correlated and un-correlated generalized random excitations are considered in the present formulation. The sensitivities of the expected number of crossings as well as the displacement RMS with respect to the design variables are also derived. The present method is applicable to stationary Guassian random excitations. Computational examples show the feasibility and efficiency of the proposed method.