【摘要】 在介绍结构试验模态分析方法的基础上,以某飞机发动机机匣为研究对象,采用锤击激励法(多点激励单点拾振)进行模态试验.在信号采集时,以激励信号与响应信号的相干函数作为检验标准,并对采集到的信号进行线性平均和加窗处理.然后利用单自由度分析方法与集总平均相结合的优势(既简单,又不漏频),分别应用峰值法和导纳圆拟合法对数据进行拟合,获得机匣的前11阶固有频率、模态阻尼比和振型图.更多还原

【Abstract】 The method of structural modal test is introduced firstly. A set of modal experiments are conducted on a casing of an airplane engine using the hammering test (Multi-input Single-output) . The coherent function is used as a basis for judgment during signal collecting. The collected signals are averaged linearly and windowed. Then the casing’s modal parameters are identified in two methods. The results are helpful for the casing’s vibration fault analysis and structural design of airplan engine.更多还原