基于多通道时间反转Lamb波的铝板小缺陷检测

发布时间：2018-03-20 01:20

本文选题：时间反转　切入点：Lamb波　出处：《实验力学》2015年06期 　论文类型：期刊论文

【摘要】：超声Lamb波具有传播距离远、衰减小等特点,广泛应用于板结构的无损检测。将Lamb波检测技术与时间反转理论相结合,能提高铝板中小缺陷的检测能力。采用多通道时间反转板中Lamb波聚焦方法对1mm厚的铝板中直径0.8mm通孔缺陷进行检测,检测结果显示多通道时间反转检测信号中形成了两处明显的聚焦,即直达波和缺陷回波聚焦,证明此方法有效提高了检测分辨铝板小缺陷的能力。最后通过直达波、缺陷回波两处聚焦的时间差和Lamb波S_0模态群速度,准确实现了铝板中小缺陷的定位。多通道时间反转Lamb波聚焦方法不仅得到了缺陷检测回波,而且准确实现了缺陷的定位,达到了提高铝板中小缺陷检测能力的目的。
[Abstract]:Ultrasonic Lamb wave is widely used in nondestructive testing of plate structures because of its long propagation distance and low attenuation. The Lamb wave detection technique is combined with time reversal theory. The method of Lamb wave focusing in multi-channel time reversal plate is used to detect the through hole defect of 0.8 mm diameter in 1mm thick aluminum plate. The detection results show that there are two obvious foci in the multi-channel time reversal detection signal, namely, direct wave and defect echo focusing, which proves that this method can effectively improve the ability of detecting and resolving small defects of aluminum plate. The time difference between the two focus points of the defect echo and the S0 mode group velocity of the Lamb wave can accurately realize the localization of the small and medium defects in the aluminum plate. The multi-channel time-reversal Lamb wave focusing method not only obtains the defect detection echo, but also accurately realizes the defect location. The purpose of improving the ability of small and medium defect detection of aluminum plate is achieved.
【作者单位】：北京工业大学机械工程与应用电子技术学院;北京市精密测控技术与仪器工程技术研究中心;
【基金】：国家自然科学基金项目(51235001,11272021,51475012) 北京市教委科技计划项目(KM201010005003) 北京市属高等学校高层次人才引进与培养计划项目(CIT&TCD201304048)
【分类号】：TG115.28

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