功率流隔振效率评价指标及其与振级落差的关系

鉴于功率流方法在隔振分析中的日益受到重视,以及以传递功率流直接作为隔振系统的设计指标存在的缺陷,因此有必要借助经典隔振理论的传递率及插入损失概念导出功率流传递率(插入损失);通过建立柔性基础隔振系统的动力学模型,应用解析分析、数值模拟和实验测试方法对功率流传递率的频谱特性进行了分析研究,对功率流传递率作为隔振设计效率指标的有效性进行了论证;针对功率流及插入损失不易测量的问题,对功率流传递率与振级落差之间的数值对应关系进行了分析比较,包括解析分析、数值模拟和实验验证。

The Power Flow Efficiency Criterion for Vibration Isolation Design and Its Relationship with Vibration Level Difference

In view of the development of power flow theory for vibration isolation analysis,the transmitted power flow which is an absolute measurement appears to be unsuitable to act as a criterion for vibration isolation design.A new vibration isolation efficiency criterion,named as power flow transmission ratio,is suggested,which is derived from the combination of the power flow method with the concept of transmission ratio and insertion loss in classical vibration isolation theories.A general dynamic model for vibration isolation systems mounted on flexible foundations is established,and the method of function analysis,numerical simulation and experimental test are adopted to investigate the property of frequency spectrum of the proposed power flow transmission ratio.It is proved that the power flow transmission ratio could be a rational and synthesized criterion for the evaluation of efficiency of vibration isolation facilities.Further work reveals the relationship between the power flow transmission ratio and the vibration level difference,regarding the inconvenience in the spot testing of power flow and insertion loss.