基于小波包分析的结构实时损伤报警数值研究

研究了基于小波包分析的结构实时损伤报警技术．利用小波分析优良的时一频局部化特性对结构振动信号进行精细分析，从而能实时地实现结构损伤报警．以简支梁裂缝为例，将环境振动信号采用小波包分解后得到小波包能量谱，采用基于Monte-Carlo方法计算得到的能量谱极值指数和变异指数2个指标作为筒支梁裂缝损伤报警的判据．该技术不需要对整体结构进行计算分析，只需要环境振动信号．计算机数值模拟表明该技术能较为敏感地发现简支梁的微小损伤，从而证实了该技术的可行性．

Numerical research on real-time structural damage alarming based on wavelet packet analysis

The real-time structural damage alarming technology is studied based on wavelet packet analysis. The structural damage alarming is performed by analyzing structural vibrational signals due to fine-time and frequency resolution of wavelet analysis. With respect to damage beams with open cracks, the energy spectrum of the wavelet packet is obtained with an environmental vibration signal by wavelet packet decomposition. The variation index and maximum index of energy spectrum based on the Monte-Carlo method are presented to judge the occurrence of beam cracks. Its advantage is that this new technique requires measured environmental signals without any analysis of the complete structure. The results obtained in the study show that a short crack can be detected effectively and efficiently, and numerical simulations verify the feasibility of the method.