圆柱形薄壳结构的试验模态分析方法研究

针对某圆柱形薄壳结构,采用锤激法和Modal Impact分析软件,分别应用SIMO、MISO和MIMO方法进行了对比试验,获得了满足模态置信准则要求的试验数据.3种方法获得的实验结果与有限元计算结果进行了对比分析.结果表明,SIMO和MISO试验方法应用于圆柱形薄壳结构的模态分析均存在局限性,或者出现"漏频"或者不能得到明显的振型.MIMO试验模态分析方法能够较好地解决以上2种方法存在的不足,在激励与响应选择适当的情况下,可以得到全面准确的模态分析结果,适用于圆柱形薄壳结构的模态分析.

Experimental modal analysis method of cylindrical thin shell structures

A comparison was made between three methods of experimental modal analysis of cylindrical thin shell structures.Hammering excitation testing and Modal Impact software was applied to single input multiple output(SIMO),multiple input single output(MISO),and multiple input multiple output(MIMO) experimental modal analysis methods on a cylindrical thin shell structure.Test data was valid according to modal assurance criterion(MAC).Results from the three experimental modal analysis methods were compared with finite element analysis,which showed that the SIMO and the MISO experimental modal analysis methods have a certain limitation for cylindrical thin shell structures.They were found to miss some natural frequencies or could not obtain some obvious modal shapes.The MIMO method could overcome the shortages of the two former methods.Ensuring correct conditions including excitation and response node locations,the MIMO experimental modal analysis method has advantages to measure valid modal parameters of modes.It is suitable for the experimental modal analysis of cylindrical thin shell structures.