Abstract: Utilizing the characteristics of periodic structures and waveform conversion function, a new floating raft with periodic truss structures is proposed. Frequency response functions of the new floating raft are calculated by the finite element method (FEM) and used in the FRF-based substructure method, which establishes a model of the assembled system involving the periodic truss raft as well as a base structure and equipment to evaluate the performance of the raft in an isolation system. Experiment is conducted to verify the simulation results. It is found that the floating raft with periodic truss structures has a better performance in suppressing vibration transmission than the traditional floating raft. When the new rafting system is composed of the floating raft and vibration isolators, the entire isolation system can reduce vibration transmission over a wider frequency band.

Key words: vibration and wave, periodic truss, raft isolation system, FRF-based substructure synthesis, vibration transmission

摘要： 利用周期结构特性和波形转换作用，提出一种新型周期桁架结构浮筏。首先利用有限元方法建立浮筏结构的数值模型并计算其频响特性，通过频响函数综合建立包含机组、浮筏和基础的振动传递模型，在隔振系统中评价新型桁架浮筏的性能，然后在此基础上，对新型桁架浮筏隔振系统进行实验验证。结果表明：周期桁架结构浮筏比传统浮筏能够更有效地抑制振动传递，组成浮筏隔振系统后，在与浮筏上下层隔振器的共同作用下，整个隔振系统在更宽的频段内对振动传递产生抑制作用。

关键词: 振动与波, 周期桁架, 浮筏隔振系统, 频响函数综合, 振动传递