| SA, which has made rapid progress recently, is served as one of structural dynamic design methods. The structural dynamic SA in project is of great importance for the study on dynamic design, optimization design, control theory and dynamic modification etc. And direct method, difference method and perturbation method for dynamic SA are adopted regular, though following shortages are obvious: only local impact of the factors on the model can be obtained; model dependence; the interval is usually the same for all of the variables and is not related to our degree of knowledge of the variables; shortage of precision and so on. Although probability distribution is involved in Mente Carlo (MC) analysis and model is independent, yet the interactions between factors are available uneasily and much is cost. Such problems are not difficult for Sobol' and FAST.Local sensitivity analysis (SA) and global SA are presented in this paper, including the mostly used means for structural dynamics behavior SA along with the their disadvantages. The emphasis is played on the discussion of Sobol' method and the Latin Hypercube sampling and the Wind-Stairs sampling characterized as small sample plus quick convergence are selected. Using Sobol' method and local SA, the impacts of non-linearity and other parameters on resonance angle frequency and transmissibility for non-linear passive vibration isolator are studied; The SA of repeated eigenvalues are discussed; The S A of random parameters for single degree of freedom-double random system are obtained; The influences on transformation frequencies for gear non-linear model are calculated. The results show that Sobol' method has the following advantages: 1. The factors' range of existence are covered; 2. All factors are allowed varying simultaneously; 3. Can be used on non-linearity, non-monotony, non-additivity models. The analysis results are important guidance for theory study on model. |
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