基于Lamb波和匹配追踪方法的结构损伤定位  

Structure Damage Localization Based on Lamb Waves and Matching Pursuits

作　　者：冯勇明[1] 周丽[1] 李真[1] 

机构地区：[1]南京航空航天大学航空宇航学院,南京210016

出　　处：《南京航空航天大学学报》2011年第2期184-190,共7页Journal of Nanjing University of Aeronautics & Astronautics

基　　金：国家自然科学基金(10572058)资助项目;航空基金(2008ZA52012)资助项目;江苏省研究生培养创新工程(CX09B-070Z)资助项目

摘　　要：提出一种基于Lamb波和字典库为Chirplet原子的匹配追踪方法的板结构损伤定位方法。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;然后建立了Lamb的弥散效应与Chirplet原子的调频斜率之间的关系,表明Chirplet原子能准确地匹配失真变形的窄带脉冲信号,并能识别Lamb波的模态;根据损伤前与损伤后的信号差,提出了一种可以分辨多损伤散射信号的损伤定位方法。最后通过数值仿真、各向同性板结构实验和蜂窝夹层复合材料结构实验,验证了该方法的可行性和有效性。A damage localization method for plate structure is developed based on Lamb waves and matching pursuit method with Chirplet dictionary.Firstly,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;Secondly,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;Thirdly,a method for damage localization is developed based on the difference between the raw signals and the damaged signals.It can distinguish the overlapped signals reflected from several damages.The effectiveness and accuracy are verified by simulation,experiments of isotropic plate structure and honeycomb sandwich of carbon fiber composite structure.

关 键 词：结构健康监测 LAMB波 匹配追踪方法 Chirplet原子 损伤定位 

分 类 号：TP206[自动化与计算机技术—检测技术与自动化装置]