Structure damage identification under ambient excitation based on wavelet packet analysis

12th International Conference on Damage Assessment of Structures

Li, Qingzhou^1 ; Li, Dongsheng^1

State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, Liaoning

116023, China^1

关键词: Ambient excitation;    Numerical results;    Positive correlations;    Structural vibrations;    Vibration response;    Wavelet Packet Analysis;    Wavelet packet energy spectrum;    Wavelet packet transforms;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/842/1/012023/pdf
DOI  :  10.1088/1742-6596/842/1/012023

来源: IOP

【 摘 要 】

There are significant changes in vibration responses when various damages appear in structures. Therefore, structural vibration responses contain rich structure damage information. In this paper, virtual impulse response of structure under ambient excitation is obtained through the inversion of a transfer function, and is decomposed into components by wavelet packet transform. Then the energy of these wavelet packet components is calculated to obtain the wavelet packet energy spectrum. And a novel damage index i.e. Energy Spectrum Anomaly Measure is developed to identify the existence of damage. Damage extent can also be inferred from the relative value of Energy Spectrum Anomaly Measure at various locations. Numerical results are presented to evaluate the effectiveness and reliability of the proposed index. It is shown that the proposed damage index works well in identifying structure damages free from the effect of various excitation and there is a positive correlation between the index and the damage severity.