浮筏隔振系统多维耦合振动特性分析

针对工程中的浮筏隔振装置,建立了柔性基础上复杂激励多维耦合隔振系统动力学模型。考虑隔振支撑多维波动效应,运用子结构导纳法推导了耦合系统动态传递方程及功率流表达式,给出了系统的功率流谱。数值模拟计算表明,复杂激励隔振系统在低频域出现多个共振峰,在高频域基础的弯曲共振模态及隔振器驻波效应使得系统功率流提高。减小隔振器刚度能明显降低系统功率流但也使驻波效应提前。增加筏体质量可明显降低系统功率流。

Characteristic Analysis of Multidimensional Coupling Vibration for Floating Raft Isolation System

A 3D dynamics model of floating raft isolation system is established. This system comprises multi-source excitation, upper isolators, rifid floating raft, lower isolators and elastic foundation. The effect of multi-dimension wave propagation is considered, and the dynamic transmisson equations and power flow expressions are provided utilizing the substructure mobility method. Results of numerical simulation show that multiple resonance peaks are excited in the low frequency domain, and the power flow is increased due to the flexural resonance modals of the elastic foundation and the standing wave effect of the isolators in the high frequency domain. Reducing the isolator stiffness can significantly decrease the power flow but also makes the standing wave effect be advanced. Power flow transmitted to the foundation can be reduced by increasing the raft mass.