有限周期梁用动力消振器抑振的特性

本文用弯曲波方法导出了多支承梁加动力消振器位移响应的普遍表达式。理论分析发现了周期结构用动力消振器抑制振动的一些新特性：（１）仅用一个动力消振器可抑制周期结构对应传递频带内的一组共振峰。被抑制的共振峰的数量与跨距的数量和消振器的布置位置有关；（２）动力消振器调谐频率与对应传递频带的第一个共振频率相关联。当动力消振器与作用在梁上的外载荷作用在同一点时，最佳调谐频率比总是大于１，否则最佳调谐频率比小于１。

REDUCTION CHARACTERISTICS OF FINITE PERIODIC BEAMS BY USE OF A DYNAMIC ABSORBER

The general equation of the displacement response of a multi-supported beam a dynamic absorber has been derived by use of fie-cural wave method. Some new and interesting characteristics of periodic beams damped by a dynamic absorber have been found:first,a group of resonance peaks within a propagation band can be reduced in level by use of only one dynamic absorber, the number of depressed peaks depending on the number of bays and the location of the absorber;secondly,the necessary tuned frequency of the dynamic absorber is related to the first resonance frequency within the corresponding propagation band. When the absorber is attached at the same point as the acting point of the external exciting force,then the optimum tune frequency ratio is large than one,otherwise it is less than one.