电磁超声兰姆波在铝板传播中的模态识别  

Modal identification of electromagnetic ultrasonic Lamb wave propagation in aluminum plate

作　　者：杨理践[1] 邹金津 邢燕好[1] 

机构地区：[1]沈阳工业大学信息科学与工程学院,沈阳110870

出　　处：《仪器仪表学报》2014年第4期909-916,共8页Chinese Journal of Scientific Instrument

基　　金：十二五国家科技部支撑计划(2011BAK06B01-03);国家863计划(2012AA040104)资助项目

摘　　要：针对兰姆波多模态特性使其回波信号难以识别的问题,研究了铝板传播中兰姆波模态的产生依据及与激励频率的关系,为电磁超声兰姆波检测仪器研制提供依据。采用分立式电磁超声兰姆波换能器结构,通过数值计算、仿真分析、实验研究互为验证的方法对兰姆波多模态的传播特性和识别进行分析,确立了换能器结构尺寸、检测频厚积点、工件被检范围等参数。结果表明,频厚积点在群速度相等的三交点处时,激励产生的单一模态兰姆波检测铝板最佳。Aiming at the problem that the echo signal of Lamb wave is difficult to be identified due to the multi-modal characteristics of Lamb wave,the modal generation basis of the Lamb wave propagating in aluminum plate and the relation between the excitation frequency and modal are studied,which provides a foundation for the development of electromagnetic ultrasonic Lamb wave detection equipment.Discrete electromagnetic ultrasonic Lamb wave transducer structure is adopted.Lamb wave multi-modal propagation characteristic and identification are analyzed through numerical calculation,simulation analysis and experimental study.The structure dimension of the transducer,the tested frequency-thickness product points,the tested workpiece range,and other parameters are determined.The results show that when the frequency-thickness product point is at the triple intersection where the group velocities are equal the generated single excitation modal Lamb wave is the best for detecting aluminum plate.

关 键 词：电磁超声 兰姆波换能器 频散曲线 模态识别 

分 类 号：TB553[理学—物理] TH83[理学—声学]