正弦扫频及随机激励颗粒阻尼器减振效果比较

用多组颗粒阻尼器对航天器上某工程结构进行减振实验研究，并用两种指标（共振峰处传递函数和测点与激振台加速度均方根之比）分别评价了正弦扫频和随机激励作用下颗粒阻尼器减振效果，发现采用正弦扫频、随机激励两种激励条件时，得出的减振效果有明显差异。为此，对差异机理进行了研究、分析。结果表明：颗粒阻尼器作为一种强非线性的被动阻尼器，其减振效果的评价不宜基于某种特定的激励条件和采用单一的评价指标，而应根据具体的使用环境选择合适的激励条件和评价指标。

Comparison of the Vibration Reduction Effects of Particle Dampers under Swept-sine and Random Excitations

The vibration reduction effects and mechanism of particle dampers have been widely studied. However, very few literatures, which investigate the influence of various excitations on the vibration reduction effect, can be found. In this paper, the experimental study on applying several particle dampers to the engineering structure of a spacecraft is performed, and two indexes （transfer function at resonance points and ratio of RMS accelerations between the measurement point and the testing bench） are used to evaluate the vibration reduction effects under swept-sine and random excitations. And a significant difference between the evaluation results under the swept-sine and the random excitations for the same particle damper is found. Thus, the mechanism of the difference is analyzed. The results indicate that the vibration reduction effect of the particle damper, as a kind of passive dampers with strongly nonlinear characteristics, is unlikely to be evaluated by a single evaluation index under a specific excitation only, but should be evaluated by a proper excitation condition and an evaluation index according to its working environment.