基于匹配追踪算法的复合材料冲击损伤成像技术

摘要

基于Lamb波和匹配追踪算法,提出了一种损伤成像方法,对复合材料冲击损伤进行在线的连续监测.首先针对Lamb波监测的特点,提出了匹配追踪方法的快速实现方案,将信号分解为多个Chirplet原子的线性组合,建立了Lamb的弥散效应与Chirplet原子的调频斜率之间的关系,模拟结果表明Chirplet原子能准确地匹配失真变形的窄带脉冲信号；根据损伤前与损伤后的信号差别,提出了一种基于Lamb波能量特征差异提取的损伤指标；进一步采用改进的RAPID算法进行损伤成像,将损伤情况可视化.结果表明所提方法可行和有效.%A damage imaging method using Lamb wave and matching pursuit method for continuous on-line monitoring of composite was proposed.First, a signal processing method is developed using matching pursuits.It can decompose Lamb signals into a linear expansion of several chirplet atoms with a fast operation speed.Second, the relationship between Lamb wave's dispersion and chirplet's chirp rate is developed.It shows that the chirplet atom can match the dispersion pulse accurately, and it can be used to identify the modes of Lamb waves.Third, according to the signal difference before and after damage, a damage index can be get from the differences in the energy characteristics of lamb wave.The image that indicates the damage can be obtained by the RAPID algorithm.The experimental results demonstrate the applicability and effectiveness of the proposed method.