舰船分散中间质量隔振系统振动特性建模

Modeling and analysis of vibration characteristics of ship decentralized intermediate mass vibration isolation system

为探究中高频扰动下舰船隔振系统多维隔振的能量波动特性,考虑隔振器的分布参数特性和基础柔性,基于该动力耦合系统中子系统结构的导纳矩阵,推导系统能流传递函数,建立了复杂激励下分散中间质量隔振系统的分布参数解析模型。联系当前舰船隔振系统的应用,设置等中间质量的浮筏隔振系统作为参照组,研究了中间结构的波动效应、隔振器驻波及中间质量与机器质量比对系统振动能量传递的影响机理。分析表明,分散中间质量避免了中间结构的波动效应,降低了子系统间发生动力耦合的可能性;分散中间质量隔振系统可以明显降低目标频段隔振器驻波发生的几率,改善了高频隔振效果;在兼顾舰船设计空间和重量的要求下,适当增大分散中间质量可以拓宽该系统的有效隔振区间。

In order to explore the energy fluctuation characteristics of multi-dimensional vibration isolation of ship vibration isolation system under medium and high frequency disturbance, considering the distributed parameter characteristics of the isolator and the flexibility of the foundation, based on the mobility matrix of the subsystem structure in this coupled system, the energy flow transfer function of the system was derived, a distributed parameter analytical model of dispersed intermediate mass vibration isolation system with complex input excitation was established. Taking into account the current application of ship vibration isolation systems, a floating raft isolation system with equal intermediate mass was selected as the reference model, the fluctuation of the intermediate structure, standing wave of the vibration isolator, the intermediate mass and the machine mass ratio on the vibration energy transfer were studied. Simulation analysis showed that the dispersed intermediate mass could mitigate the occurrence of standing wave of vibration isolator in the target frequency band and improve the vibration isolation result of high frequency, the dispersed intermediate mass also avoided the fluctuation effect of the intermediate structure and reduced the possibility of dynamic coupling between subsystems. Under the requirement of both ship design space and weight, appropriately increasing the dispersed intermediate mass can broaden the effective vibration isolation interval of the system.