摘要
在激励满足白噪声的假设下 ,可以将互相关函数代替脉冲响应函数用于多参考点最小平方复指数法 ,单独利用响应数据求出系统的自然频率和阻尼 ,但无法获得模态振型。该文提出了一种用互功率谱求振型的方法 ,并对此理论进行了详细推导 ,以一悬臂梁为例对该方法进行了试验验证。结果表明 ,采用该方法能够有效地识别出模态振型 ,从而弥补了复指数法在未知激励下进行模态分析的不足。
The cross correlation functions is applied to PRCE method to extract the natural frequencies and damping from output only under the white noise excitation,but the mode shape can't be determined. This paper gives a theoretical formulation for the extraction of mode shape by fitting the cross power spectra of the outputs and a cantilever beam is analysed. The results show that the present method can identify the mode shape accurately and complement the use of PRCE under unknown excitation condition.
出处
《南京理工大学学报》
CAS
CSCD
2000年第2期117-120,共4页
Journal of Nanjing University of Science and Technology
基金
航空工业总公司九五规划项目
关键词
模态分析
环境激励
振型识别
cross power,data,fitting,modal analysis
ambient excitation,complex exponential method
