实验模态分析是综合运用线性振动理论、动态测试技术、数字信号处理和参数识别等手段,进行系统识别的过程.模态分析是有效的结构检测和安全评估的方法之一,它是根据测量模态参数(固有频率、阻尼比、振型、模态刚度、模态质量)相对于正常值产生的变化,并通过相关分析与识别来判断结构安全程度的一种先进方法.本文通过对网架模型结构进行试验模态分析,研究了试验模态技术在实际运用中的试验方法,识别系统的模态参数并与有限元分析进行比较,有限元结果与实测频率有一定的不同,但前四阶模态频率的差值百分比均在9％以内,说明实测的结果与有限元分析是比较吻合的.%Experimental modal analysis is the integrated use of linear vibration theory, dynamic testing technology, digital signal processing and parameter identification methods, the system identification process. Modal analysis is an effective structure monitoring and safety assessment method,which is based on measurement of modal parameters (natural frequencies, damping ratios, mode shapes, modal stiffness, modal mass) relative to the normal changes resulting. And through correlation analysis and identification to determine the structural safety of an advanced method. This article describes the theory of modal analysis , and the grid model the structure of experimental modal analysis of the experimental modal test in the practical application of methods and means to identify the modal parameters of the system and with the finite element analysis were compared. Finite element results with the measured frequency has some different, but the difference percentage of first four modal frequencies is less than 9% .indicating that the measured results with finite element simulation is more consistent.
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