Optimal Mother Wavelet Selection for Lamb Wave Analyses
Optimal Mother Wavelet Selection for Lamb Wave Analyses
复制标题
Lamb 波分析的最佳母小波选择
DOI：
10.1177/1045389x09102562
复制
发表时间：
2009-07-01
影响因子：
2.7
通讯作者：
Ye, Lin
中科院分区：
文献类型：
--
作者：
Li, Fucai;Meng, Guang;Ye, Lin
结构健康监测（SHM）系统在疲劳寿命和损伤累积预测中起着重要作用，通常由传感器网络收集结构响应信号和数据分析算法解释组成。小波变换（Wavelet transform， WT）作为一种高效的信号处理手段在SHM中得到了广泛的应用，其中基于最优母小波的小波变换可以进行高精度的特征提取。本文的目的是为了提供SHM Lamb波分析中最优母小波选择准则，其动机是由于Lamb波的传播速度非常快，Lamb波分析中的小误差会导致损伤定位的大误差。建立了小波系数香农熵的概念，用于标定所选母小波的优化程度。作为应用，使用所提出的准则选择的各种母小波应用于从含有分层的CF/EP复合材料层合板中获得的Lamb波信号。利用最优母小波，高精度地获取分层产生的Lamb波的基本信息。结果表明，该方法能够为兰姆波分析选择最合适的母小波，从而实现损伤定位。
Structural health monitoring (SHM) system, usually consisting of a sensor network for collecting the structural response signal and data analysis algorithms for interpreting the signal, plays a significant role in fatigue life and damage accumulation prognostics. Wavelet transform (WT) has gained popularity as an efficient means of signal processing in SHM, in which an optimal mother wavelet-based WT can carry out feature extraction with high precision. This article is to provide criteria of optimal mother wavelet selection in Lamb wave analysis for SHM, motivation of which is that small error in Lamb wave analysis can result in much larger error in damage localization because of very fast propagating velocities of Lamb waves. A concept, Shannon entropy of wavelet coefficients, was established to calibrate the degree of optimization of the selected mother wavelet. As application, various mother wavelets selected using the proposed criteria were applied to Lamb wave signals acquired from CF/EP composite laminates containing delamination. With the optimum mother wavelet, the essential information of the delamination-generated Lamb waves was achieved with high precision. The results demonstrate the excellent capacity of the approach for selecting the most appropriate mother wavelets for Lamb wave analyses and therefore damage localization.