A study on identification-probability histogram method for modal identification of structures subjected to ambient excitations

作者：Chen, Tai-Cong; Li, Ying-Ying; Su, Cheng^*; Ma, Hai-Tao

来源：Journal of Vibration Engineering, 2016, 29(4): 561-567.

DOI：10.16385/j.cnki.issn.1004-4523.2016.04.001

• Ambient excitation
• Anti-noise capacity
• Frequency tolerance
• Identification probability
• Modal identification
• Stabilization diagrams
• Stochastic subspace
• Stochastic subspace methods

During the modal identification of a structure subjected to ambient excitations, the system order as a crucial computation parameter is not easy to be determined, and the stabilization diagram method based on assumed system orders is often adopted to help the identification. But how to distinguish the stabilization axes is in fact subjective, which may lead to possible inclusion of pseudo vibration modes instead of real modes into the final results. To avoid these problems, an identification-probability histogram (IpHist) method in use of the data mining technique is proposed in the present paper. Firstly, the stochastic subspace method is applied to identify the alternative modes with different assumed system orders. Then, all the alternative modes are clustered into several categories by using the criteria of frequency tolerance and MAC tolerance, and the identification probability of each category is obtained along with the corresponding identification-probability histogram. Finally, the clustered modes with large identification probability are chosen to be the structural modes. By taking a four-story Benchmark model provided by the IASC-ASCE structural health monitoring workgroup as example, numerical results are presented to illustrate the effectiveness and anti-noise capacity of the proposed IpHist method for modal identification of structures subjected to ambient excitations.

• 出版日期2016-8-1
• 单位华南理工大学