不同材料储罐底板中Lamb波频散曲线的绘制与对比分析

Lamb波频散特性是进行Lamb波无损检测的前提,为了给储罐底板的Lamb波检测提供参考依据,根据Rayleigh-Lamb方程,采用二分法求解无限大板中Lamb波的频散曲线,再通过Matlab软件对求解过程进行编程,绘制出Lamb波在不同储罐底板材料中传播的相速度和群速度曲线。为便于对比分析,绘制出各种材料S0模态相速度频散特性曲线及A0模态相速度频散特性曲线。通过对不同材料频散特性的分析与比较,获取对各种材料Lamb波检测可选的模态为S0和A0模态,针对S0模态和A0模态分别给出了每种材料在实际检测中可选的频厚积范围。

Drawing and comparative analysis of Lamb wave dispersion curves in tank bottom plate of different materials

Lamb wave dispersion characteristic is the precondition of lamb wave nondestructive detection. The article provides an important reference for the Lamb wave detection of the tank bottom plate. Based on the Rayleigh lamb equation, Lamb wave dispersion curves in the infinite plate are obtained according to dichotomy in this paper. Through programming the Matlab software for the solving process, phase velocity curves and group velocity curves that Lamb wave propagate in different tank bottom plat materials are drawn. In order to facilitate the comparison and analysis, the S0 mode phase velocity dispersion characteristic curve and the A0 mode phase velocity dispersion characteristic curve of various materials are also plotted. Through the analysis and comparison of the dispersion characteristics of different materials, the optional mode for Lamb wave detection for different materials are S0 mode and A0 mode. For S0 mode and A0 mode, the optional frequency-thickness product ranges for each material in the actual detection are given, respectively.