机械设备隔振系统的子结构建模方法研究

基于频响函数(FRF)的子结构方法是分析复杂组合结构的有效方法之一,其基本原理是使用单个非耦合的分量FRF通过阻抗或导纳方程构成总的系统响应。通过采用自由速度描述机械设备的激励特性,采用四端参数描述隔振器的阻抗特性,建立了机械设备隔振系统完整的子结构模型。经实测,获得了设备机脚的自由速度以及基座等结构的导纳矩阵,计算获得设备弹性安装后机脚和基座安装点的响应,并与测试结果进行了比较。分析表明,结果吻合较好,计算值与测试值的偏差基本在3 dB以内,能够满足工程要求。

FRF-Based Substructure Technique for Modeling Machinery Isolation System

The transfer function synthesis method is one of the most powerful methods in analyzing the responses of complex built-up structures.The fundamental concept of this technique is to utilize individual uncoupled component FRFs to construct the total system response via either an impedance or mobility-type computational equation.This paper introduced Free Velocity to describe the vibration source of machine,four-pole parameter to describe the machinery impedance of isolator,then formulating exact model of machinery isolation system using FRF based substructure technique.Free Velocity of machinery and mobility of base were obtained by test,then predicting the response velocity of machinery and base by FRF based substructure technique.The comparison of response velocity obtained by the proposed method and the measurements shows that the error is largely less than 3 dB.