基于锤击激励的随机子空间法模态参数识别

Modal Parameter Identification Based on Impact Excitation Stochastic Subspace Method

结构模态参数识别是结构健康监测领域研究中的重点,检测得到的模态参数是判定结构健康状况的重要依据,以钢筋混凝土简支梁模型为研究对象,采用Midas/Civil有限元软件进行模态参数分析,并以有限元计算结果为参考,采用锤击激励法进行简支梁的模态实验,并分别用随机子空间法和特征系统实现算法识别了整体结构的模态参数,两者误差最大不超过6%,说明锤击法的模态试验是成功的,试验结果可以为同类结构的模态试验分析提供参考。

Modal parameter identification is the focus of the research field of structural health monitoring and modal parameters obtained are an important basis for determining the degree of structural health. With the reinforced concrete simply supported beam model as the study object, the finite element software Mi- das/Civil was adopted for the analysis of modal parameters. Finite element calculated results were consul- ted and the impact excitation method was adopted to conduct modal experiments on simply supported beams,and the stochastic subspace identification method and the Eigen system realization algorithm were applied to identify the modal parameters of the overall structure. The maximum error was less than 6 %, which showed that the modal test of the impact excitation method was successful and the test results pro- vided a solid basis for the modal test of similar structures.