Stochastic response sensitivity of secondary systems to primary structural uncertainties

Response characteristics of secondary systems anchored or attached to a primary structure can be strongly dependent upon parameter values assumed for the secondary and primary systems. For design and performance evaluations, it is thus of practical interest to develop sensitivity factors relating response behavior of a secondary system to structural parameter variations. In this paper, the use of spectral moments as peak response sensitivity factors is proposed when the primary-secondary system is subjected to random loading. It is shown that they provide a consistent and quantitative measure of relative importance of parameter uncertainties in the design and performance evaluation of secondary systems. These results are particularly useful to designers in order to determine the desired dynamic characteristics of secondary systems, and to determine the degree of design response spectrum broadening needed.