基于光纤光栅和小波包分析的结构损伤探测

Structural Damage Detection based on Fiber Bragg Grating and Wavelet Packet Analysis

以光纤光栅为传感元件、小波包分析为信号提取工具,获取了智能材料四边简支板损伤前、后的动态应变信号检测方法,并采用耦合神经网络方法对智能材料四边简支板结构进行了损伤识别分析。结果表明,光纤光栅可非常灵敏地检测出智能材料内部的动态应变信号,小波包信号处理方法可获得大量反映结构损伤特征的有效信号;随着损伤孔径的增大,耦合神经网络损伤识别的精度提高,可得到损伤的位置和大小的信息。研究结果在大型工程结构的健康监测中具有重要的潜在应用价值。

A method of measuring dynamic strain signals before and after damage of smart materi- al four-side simple supported plate was developed in this paper. The fiber Bragg grating array and couple neural network were used as senor and signal extraction tool, respectively. The structural damage recognition of the four-side simple supported plate was carried out with coupled neural network method. The results show that the fiber Bragg grating array can sensitively detect the dynamic strain signals. The signal treatment method based on the wavelet packet analysis can ob- tain a lot of useful characteristic signals with high precision. The couple neural network can get accurate information on location and size of structural damage. The precision of structural dam- age recognition based on the couple neural network gradually rises with damage size increasing. These results have importantly potential applications in structural health monitoring of large- scale projects.