Lamb波结合相控阵技术的结构损伤检测  

Application of Phased Array Technique in Lamb Wave Based Structural Damage Detection

作　　者：张宇[1] 余龙[1] 闫云聚[1] 

机构地区：[1]西北工业大学力学与土木建筑学院,西安710129

出　　处：《振动．测试与诊断》2013年第6期977-980,1092-1093,共4页Journal of Vibration,Measurement & Diagnosis

基　　金：国家自然科学基金资助项目(50905141);高等学校博士学科点专项科研基金(优先发展领域)资助项目(20126102130004);教育部新世纪优秀人才资助项目(NECT-10-0078);西北工业大学基础研究基金资助项目(NPU-FFR-JC02110258)

摘　　要：在相控阵技术应用于Lamb波的结构损伤检测中考虑到波瓣宽度对检测精度的影响,激励的Lamb波被集中在某一特定方向上传播并对结构进行快速扫描,从而对结构损伤进行定位。然而,波在传播过程中当波束扫描偏离法线方向时,阵列的主瓣宽度将变宽,增益下降,旁瓣则增大造成能量泄露并降低检测精度。因此,为了提高检测精度,利用窗函数对激励信号进行修正,但通过加窗来降低旁瓣是以展宽主瓣为代价的。笔者对不同窗函数进行比较,修正后的增益计算结果与原先进行对比,计算的精度得到有效提高。在已有的利用Lamb波检测的基础上结合相控阵的优点将其引入到结构的损伤检测中,以一个仿真模型为例验证,得到了较好的检测效果。Beam width detection accuracy which is taken into account during phased array technique,is used for Lamb wave based structural damage detection.Lamb wave could be focused at a specified direction during its propagation on the plate,and the signals received from healthy and damage structures are compared respectively,so as to locate structural damage.However,the mail lobe width would be broadened when the beam scanning is deviated from the normal direction,and the energy leakage of wave side lobes would reduce the detection accuracy.Thus,window function is used to modulate excitation signal. The results show that the accuracy of the calculation is improved.Finally,a numerical simulation demonstrates that this method has a great application potential in structural damage detection.

关 键 词：LAMB波 相控阵 波瓣宽度 结构损伤检测 

分 类 号：O329[理学—一般力学与力学基础] TB553[理学—力学]