复合材料板Chirp激励的Lamb波成像技术研究  

Research on Lamb wave imaging technique for composite plate based on chirp excitation

作　　者：刘增华[1,2] 穆云龙[1,2] 宋国荣[1,2] 何存富[1,2] 吴斌[1,2] 

机构地区：[1]北京工业大学机械工程与应用电子技术学院,北京100124 [2]北京工业大学北京市精密测控技术与仪器工程技术研究中心,北京100124

出　　处：《仪器仪表学报》2015年第9期1961-1971,共11页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(50975006;11272021;51475012);北京市属高等学校高层次人才引进与培养计划(CIT&TCD201304048);北京市教委(KM201010005003)项目资助

摘　　要：作为一种快速、高效的无损检测方法,Lamb波技术在结构健康监测领域具有巨大的应用潜力并受到广泛关注。采用线性宽带Chirp信号作为激励信号,替代传统的窄带Tone burst信号。响应信号经过后处理可以解调出其带宽范围内任意中心频率的等效Tone burst响应信号。优化设计一种压电传感器,能够在低频段激励和接收纯净的A0模态。由于A0模态对板中缺陷非常敏感,使信号更便于分析。将这种传感器按照稀疏阵列的形式布置于准各向同性复合材料板上,对模拟缺陷进行检测。通过实验所得Chirp信号的检测数据解调出多个中心频率下的响应信号,结合椭圆成像技术和数据融合方法进行缺陷成像,实现了板中缺陷定位,并且多个频率下响应信号融合后的成像结果具有更高的分辨率、对比度和定位精度。As a rapid and efficient nondestructive testing method, Lamb wave technology possesses great application potentials in structural health monitoring fields and has been paid considerable attention. In this paper, the wide-band linear chirp signal is chosen as the excitation signal to replace traditional narrow band tone burst signal. Through post-processing, the response signal of the chirp signal can be demodulated, and the equivalent tone burst response signals with any center frequencies in the bandwidth range of the chirp signal can be extracted. A kind of piezoelectric transducer is designed optimally, which can excite and receive the pure A0 mode signal in low fre- quency range. The A0 mode signal is very sensitive to the defects in plates, which makes the signal to be analyzed more conveniently. These developed piezoelectric transducers were arranged on a quasi-isotropie composite plate sparsely, and the simulated faults were detected. The detection data of the chirp signal obtained in the experiment were demodulated, and the response signals with multiple center frequencies were achieved. The elliptic imaging technique and data fusion method were combined to perform defect imaging, and the defect location in the composite plate was realized. The imaging results from the signal fusion of the response signals with multiple frequencies have higher resolution, contrast and location accuracy.

关 键 词：LAMB波 CHIRP信号 复合材料板 椭圆成像 缺陷检测 

分 类 号：TB302.5[一般工业技术—材料科学与工程] TH878.2[机械工程—仪器科学与技术]