浮筏隔振系统导纳功率流特性研究

【作者】 行晓亮；

【导师】 王敏庆；

【作者基本信息】 西北工业大学 ， 环境工程， 2005， 硕士

【摘要】 浮筏隔振系统是一种较为有效的振动控制系统,将近四十年来在航海工程机械的减振降噪应用中取得了非常显著的效果。然而与工程应用实际相比,理论研究则显得较为滞后,因此研究这一系统的隔振机理对于降低振动传递、减小船舶结构振动,从而提高军用舰艇的战斗力、改善海员及乘客的生活环境,均具有重要意义。 导纳功率流法是复杂结构振动分析的有效方法,它以瞬时功率的周期平均值来分析结构振动,由于该物理量同时考虑了力和速度的信息,所以在振动分析和控制方面,比单纯控制力或速度更具有实际意义,并且由于功率是一个单一的量值,因此它能给出振动传输的一种绝对度量,并可用仪器测量。此外,它能清楚地指明功率流的流向,哪一台机器、哪一个部分以至于哪一个支承点对结构注入了最大功率均可一目了然,据此我们可以有的放矢地进行振动控制。 本文以船舶动力设备减振降噪为实际背景,建立了多扰动源减振浮筏系统的理论研究模型,从子结构的导纳入手,采用导纳功率流方法推导了由振源输入浮筏系统、传递到筏体及基础结构的功率流表达式。与此同时,文中以把握浮筏隔振系统的功率流传递特性、减振机理和探讨提高隔振效果的设计途径为目的,在研究有限非对称布置系统的基础上,建立了考虑筏体和基础结构动力特性的振子力学模型,并使用这一模型从功率的角度研究了浮筏隔振系统振动传输特性,推导了稳态随机力激励下浮筏隔振系统的振动响应和振动功率流表达式,并通过数值仿真分析了筏体和隔振器等结构参数改变对结构输入功率、振动能量传递的影响。最后本文建立了浮筏隔振系统实验研究模型,实验测量了浮筏系统激励源上的输入导纳、传递导纳以及输入浮筏系统和传递到基础结构的功率流,探索了减振浮筏的功率流实验方法。更多还原

【Abstract】 Floating raft vibration isolation system is a good approach of controlling vibration, and this system has been successfully used in navigation. Compared with engineering application, the theory research apparently is very slowly. So, it is very useful that to study the theory of the floating raft vibration system, because it can reduce the vibration of the ship machine, can advance the battle effectiveness of naval vessel, and approve .the life condition of sailor.Mobility power flow approach is originally defined as the time average of instantaneous power, is an effective method for vibration analysis and control of complex structure.It is great significance to understand the mechanism of floating raft for reducing the vibration in building and ship structure, for this purpose, a theoretical research model-raft system, consisting of many machines, is set up. From sub-structure analysis, this thesis deduces the power input to the system and power transmitted to the mid-structure or base structure. Both the forces and the velocities at the installation positions in mid-structure and base structure of raft system are solved. Based on the limited nonsymmetrical distributed system, a vibration model that including mid-structure and base structure dynamical characteristics has been built up. And the vibration transfer characteristics of floating raft vibration isolation system with this model have been studied. The vibration response and vibration power flow equation has been concluded under stable random effect, and the effect of vibration power transfer has been analyzed since raft’s parameter has been changed.更多还原