基于小波包频带能量检测技术的结构损伤诊断

Damage diagnosis of structure based on wavelet packet frequency band energy detecting technology

小波包变换能将振动信号按任意时频分辨率分解到不同频段,而各频段信号的能量变化包含着丰富的信息.以悬臂梁为实验对象,对不同损伤程度下的振动信号进行小波去噪后,通过4尺度小波包分解和重构,得到了其能量谱图.实验结果表明:损伤程度不同,小波包能量谱图明显不同.因此可将敏感频带的能量值作为损伤程度的特征值进行损伤诊断.

The transform of wavelet packet can decompose signals into different frequency bands at random time-frequency resolutions, while the energy changes of signals at various frequency bands contain rich information that may be used in damage frequency band energy analysis combined with ver beam, and the vibration signal of it under wavelet transform. A four measure wavelet pac diagnosis. A detecting technique based on wavelet packet experiments is given. The experimental object is a cantile- different damage conditions was collected and denoised by ket is applied into the decompositions and reconstruction of the signal, and the energy spectrum is obtained. As experiments demonstrate： under different conditions of structure, there are evident differences among the energy spectrum. Therefore, the energy components can be chosen as damage indices. damage sensitive