基于有限元方法的薄板超声Lamb波频散曲线计算  

Calculation of Ultrasonic Lamb Wave Dispersion Curve of the Thin Plate by the Finite Element Method

作　　者：陈亮[1] 王恩报 马豪[1] 董彦磊[1] 王瑜[1] 

机构地区：[1]电子科技大学机械电子工程学院,四川成都611731

出　　处：《实验室研究与探索》2014年第11期28-31,共4页Research and Exploration In Laboratory

基　　金：四川省应用基础计划(2010JY0053);中央高校基本业务费项目(ZYGX2012J097);成都市科技局项目(11DXYB281JH-027);电子科技大学教育发展基金项目(2013XJYEL024)

摘　　要：采用基于有限元方法对薄板超声Lamb波频散曲线进行计算是一种有效的方法。首先,对自由边界条件下Raleigh-Lamb频率特征方程进行数值求解,求得铝板中超声Lamb波的理论频散曲线。然后,利用有限元数值模拟方法,研究不同频厚积时超声Lamb波在薄板结构中的传播过程,并分别计算10组不同频厚积对应的群速度和相速度大小,绘制了频厚积在2 MHz·mm以下范围的频散曲线。结果表明,该频散曲线与通过频率特征方程求解的超声Lamb波理论频散曲线相吻合。Studying the propagation characteristics of ultrasonic Lamb waves in the thin plate structure is crucial for the process of Lamb wave ultrasonic nondestructive testing. Using finite element method to calculate ultrasonic Lamb wave dispersion curve of the thin plate is an effective method. At first,theory of ultrasonic Lamb wave dispersion curve in aluminum plate was plotted by the numerical calculates for Raleigh-Lamb frequency characteristic equation on free boundary conditions. Then the finite element numerical simulation method was used to study propagation of ultrasonic Lamb waves in thin structures at different frequencies thick plot,and 10 different frequencies thick plot corresponding size of the group velocity and phase velocity were calculated. Based on the calculation the group velocity and phase velocity data,disperse curves were plotted in the following range of frequency 2 MHz · mm thick plot. Calculation results showed that the dispersion curves and the ultrasonic Lamb wave theory by frequency characteristic equation dispersion curves were coincident.

关 键 词：超声 LAMB波 频散曲线 有限元 薄板 

分 类 号：TH7[机械工程—仪器科学与技术]