Abstract: There are larger loss factor values and wider application advantages with regard to the vibration–noise damping reductive structures with tubular symmetrical shapes. But on the other hand, there also are intractable problems on which the structural parameters are tightly coupled each other and the parameters are hard to be selected reasonably. In order to solve the problems, structural parametric models in which the structures are possessed of spacing-element and non-spacing-element types with tubular symmetrical shapes are established. The characteristics of structural parameters and their effects to structural loss factors are analyzed for the types of structures with single and multiple damping layers, and the optimizations are carried out as for the parameters. A new type of damping vibration–noise damping reductive equipment, which is applied to the steering mechanisms in urban light trains, is developed according to above research conclusions. And the tests are performed in terms of their realistic working conditions. The dynamic tests using frequency sweep methods are performed for the equipment so that optimized structural models are tested and verified and the performances of the equipment are examined. The results show that the both of testing data and theoretic models are better coincidence.

Key words: Damping Vibration–noise-damping reduction, Optimization, Tubular symmetrical structure