An approach to reliability-based optimization of redundant structures

Abstract This paper proposes an optimum design procedure for redundant structures with the constraints on the formation probabilities of structural failure modes. Although there exist numerous failure modes in a large-scale redundant structure, it is found that only a representative group consisting of some dominant failure modes needs to be considered in the optimization process. The proposed procedure introduces such dominant modes step by step from various design stages to keep the total number of the constraints at a minimum level. A branch-and-bound technique is used to identify dominant failure modes in a design state. Some analytical methods are discussed for the calculation of the formation probabilities of failure modes in the optimum design process. A numerical example is given to illustrate the effectiveness of the proposed procedure.