A time reversal damage imaging method for structure health monitoring using Lamb waves  

作　　者：张海燕 曹亚萍 孙修立 陈先华 于建波 

机构地区：[1]School of Communication and Information Engineering,Key Laboratory of Specialty Fiber Optics and Optical Access Networks,Shanghai University

出　　处：《Chinese Physics B》2010年第11期448-455,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos. 10874110 and 10504020);Shanghai Leading Academic Discipline Project,China (Grant No. S30108);Science and Technology Commission of Shanghai Municipality,China(Grant No. 08DZ2231100)

摘　　要：This paper investigates the Lamb wave imaging method combining time reversal for health monitoring of a metallic plate structure. The temporal focusing effect of the time reversal Lamb waves is investigated theoretically. It demonstrates that the focusing effect is related to the frequency dependency of the time reversal operation. Numerical simulations are conducted to study the time reversal behaviour of Lamb wave modes under broadband and narrowband excitations. The results show that the reconstructed time reversed wave exhibits close similarity to the reversed narrowband tone burst signal validating the theoretical model. To enhance the similarity, the cycle number of the excited signal should be increased. Experiments combining finite element model are then conducted to study the imaging method in the presence of damage like hole in the plate structure. In this work, the time reversal technique is used for the recompression of Lamb wave signals. Damage imaging results with time reversal using broadband and narrowband excitations are compared to those without time reversal. It suggests that the narrowband excitation combined time reversal can locate and determine the size of structural damage more precisely, but the cycle number of the excited signal should be chosen reasonably.This paper investigates the Lamb wave imaging method combining time reversal for health monitoring of a metallic plate structure. The temporal focusing effect of the time reversal Lamb waves is investigated theoretically. It demonstrates that the focusing effect is related to the frequency dependency of the time reversal operation. Numerical simulations are conducted to study the time reversal behaviour of Lamb wave modes under broadband and narrowband excitations. The results show that the reconstructed time reversed wave exhibits close similarity to the reversed narrowband tone burst signal validating the theoretical model. To enhance the similarity, the cycle number of the excited signal should be increased. Experiments combining finite element model are then conducted to study the imaging method in the presence of damage like hole in the plate structure. In this work, the time reversal technique is used for the recompression of Lamb wave signals. Damage imaging results with time reversal using broadband and narrowband excitations are compared to those without time reversal. It suggests that the narrowband excitation combined time reversal can locate and determine the size of structural damage more precisely, but the cycle number of the excited signal should be chosen reasonably.

关 键 词：Lamb wave time reversal damage imaging structure health monitoring 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]