二维结构损伤的主动Lamb波定位技术研究

Study on Two-dimensional Damage Location in Structure Based on Active Lamb Wave Detection Technique

将Lamb波主动监测技术应用于复合材料损伤检测中,对二维结构损伤进行定位研究。利用压电陶瓷片作为驱动器和传感器,对结构损伤前后的传感信号做信号差,采用3种常用的信号时间延迟估计方法,比较这3种方法计算差信号和健康信号的时间延迟的损伤定位效果,其中定位方法采用了椭圆技术。详细介绍了这3种时间延迟估计方法的原理以及损伤定位结果的分析。实验结果表明在信号的信噪比较小的情况下,采用小波变换法能更准确地识别出复合材料冲击损伤的位置。实验数据验证了该方法的有效性。

This study treats with active Lamb Wave detection technique used in damage detection for composite materials, and ellipse technique in the two-dimensional structural damage localization. Three methods are applied to compute the time delay between differential signal and health signal. Experiments results demonstrate that wavelet transformation analysis has an advantage over the others in the precise damage localization with small Signal-to-Noise ratio.