CSM在基于Lamb波的结构损伤检测中的应用  

APPLICATION OF CSM IN LAMB WAVE BASED STRUCTURAL DAMAGE DETECTION

作　　者：张宇[1,2] 闫云聚[1] 余龙[1] 袭著有[1,3] 

机构地区：[1]西北工业大学力学与土木建筑学院,西安710129 [2]西安财经学院工程管理系,西安710100 [3]辽宁工业大学理学院,辽宁锦州121001

出　　处：《工程力学》2015年第6期22-27,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(50905141);高等学校博士学科点专项基金项目(优先发展领域)(2012610213004);新世纪优秀人才计划项目(NECT-10-0078);西北工业大学基础研究基金项目(NPU-FFR-JC20110258)

摘　　要：在基于Lamb波的结构损伤检测中往往不可避免地遇到结构中多个损伤引起的反射波信号相干问题而对检测精度造成影响。考虑到阵列信号处理中的空间谱估计可以对信号源进行辨别和定位,尤其是在信号的波达方向(Direction of Arrival,DOA)估计上的优越性,将其应用于基于Lamb波的结构损伤检测中以获得准确的结构损伤信息。于是,该文采用空间谱估计中相干信号子空间方法(Coherent Signal Subspace Method,CSM)解决了相干信号问题。以一个损伤结构的仿真分析为例,验证了CSM方法在基于Lamb波的结构损伤检测中处理相干信号的可行性。结果表明,无论是结构损伤和边界反射引起的信号相干或两个结构损伤引起的信号相干,依然可以通过该方法获得准确的结构损伤信息。Signals reflected by structural damage are inevitably coherent during wave propagation in Lamb wave based structural damage detection, which will decrease detection accuracy. Considering the superiority of spatial spectrum estimation in signal source identification and location, especially in the signal direction of arrival(DOA), spatial spectrum estimation was applied to locate structural damage so as to obtain accurate damage information in Lamb based structural damage detection. Thus, a coherent signal subspace method(CSM) in spatial spectrum estimation was developed so as to solve coherent signal problems. The numerical simulation of a damaged aluminum plate illustrated the feasibility of the CSM in the spatial spectrum estimation of coherent signals. It indicates that no matter the coherent signals were reflected by the boundary and structural damage or the two types of damage, all the structural damage information could be well obtained by this method.

关 键 词：阵列信号处理 空间谱估计 LAMB波 CSM DOA 结构损伤检测 

分 类 号：TU317[建筑科学—结构工程]