板中孔状缺陷的超声导波检测试验研究  

Experimental Research on Hole-like Defect Detection in Plate Based on Ultrasonic Guided Waves Technique

作　　者：刘增华[1] 赵继辰[1] 吴斌[1] 何存富[1] 

机构地区：[1]北京工业大学机械工程及应用电子技术学院,北京100124

出　　处：《北京工业大学学报》2011年第1期27-32,共6页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(50975006;10972014);北京市自然科学基金资助项目(2072003);北京市优秀人才培养资助项目(20081B0501500173);北京市教委科技计划项目(KM201010005003);北京市科技新星计划资助项目(2008A015)

摘　　要：为了实现对板类结构的主动健康监测,采用附着在结构上的压电陶瓷晶片激励和接收导波模态,选取合适模态用于板中缺陷的识别和评估.理论分析结果表明,在低频范围内,相对于A0模态,以面内位移为主、频散小的S0模态更适合于铝板的缺陷检测.利用直径11 mm,厚0.4 mm的压电陶瓷晶片在1 mm厚的铝板上激励和接收得到适合缺陷检测的频率300 kHz的S0模态.在此基础上,在铝板中加工一孔状缺陷,分析了S0模态的缺陷检测能力,并进一步研究了缺陷直径对接收到的导波信号幅度的影响.实验结果表明,利用一发一收法得到的Lamb波模态可以用于铝板中的缺陷检测,并且缺陷回波的幅度可实现对缺陷大小的表征.To achieve active health monitoring of plate-like objects, piezoelectric ceramic wafers bonded in the structures are applied for excitation and reception of guided wave modes and proper modes are optimized for identification and evaluation of the defects. According to the theoretical prediction, compared with A0 mode, SO mode in a low frequency range with dominant in-plane displacement and low dispersion is suitable for defect detection in the aluminum plate. The piezoelectric ceramic wafers 11 mm in diameter and 0.4 mm in thickness are used for excitation and reception of SO mode at 300 kHz, which is suitable for defect detection in aluminum plates with a thickness of 1 mm. Based on the experimental results, an artificial hole-like defect is machined in the plate for verifying the ability of defect detection using SO mode, and the effect of the defect diameter on the amplitudes of received guided wave signals is further analyzed. Experimental results show that Lamb wave modes can be applied for defect detection in the aluminum plate using the pitch-catch method and defect characterization can be achieved based on the amplitudes of the received echoes.

关 键 词：超声导波 频散 模态 

分 类 号：TB132[理学—物理] TB559[理学—应用物理]