基于超声Lamb波截止频率的双层薄板各层厚度表征  

Characterization of each layer thickness of the bi-layer thin plates based on the cut-off frequency of the ultrasonic Lamb waves

作　　者：潘蕾 沈中华[1] 刘祥恩 阚威威 PAN Lei;SHEN Zhonghua;LIU Xiang′en;KAN Weiwei(School of Science,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学理学院,南京210094

出　　处：《无损检测》2022年第6期6-9,14,共5页Nondestructive Testing

基　　金：国家自然科学基金项目(61975080)

摘　　要：双层薄板材料在建筑、航空航天、镀膜等行业都有非常广泛的应用,厚度是板状材料的重要参数,因此对厚度进行表征具有重要意义。提出了一种基于超声Lamb波截止频率测量双层薄板各层厚度的方法,推导出双层薄板Lamb波截止频率与两板厚度比的关系,各层厚度可用总厚度和两板厚度比表征。通过理论公式计算了不同厚度比的双层薄板(非铝/铝)Lamb波一阶反对称模态(A_(1))的截止频率,得到A_(1)模态截止频率随厚度比变化的曲线,并分析了非铝板横波速度对其变化的影响。Bi-layer thin plates are widely used in the construction industry,aerospace,coating technology,etc.The thickness is an important parameter of slab materials,so the characterization of thickness is of great significance.This paper proposed a method for measuring the thickness of each layer of the bi-layer thin plates based on the cut-off frequency of ultrasonic Lamb waves.It was theoretically deduced that cut-off frequency of the bi-layer thin plates is related to the thickness ratio of the two plates.The thickness of each layer was characterized by the total thickness and the thickness ratio of the two plates.The cut-off frequencies of the first-order anti-symmetric mode(A_(1))of the bi-layer thin plates(non-aluminum/aluminum)with different thickness ratios were calculated by theoretical formulas,resulting in a curve of the A_(1)mode cut-off frequency with the thickness ratio of the two plates,and at the same time the effect of non-aluminum plate’s transverse wave velocity on its change was analyzed.

关 键 词：LAMB波 截止频率 双层薄板 A 模态 

分 类 号：TB302.5[一般工业技术—材料科学与工程]