【摘要】 为了给料位测量的实验研究提供理论上的依据,该文以实验室装置为对象,在合理的简化假设条件下,采用波动理论结合相应的边界条件,建立了板中Lamb的色散方程。通过对方程的求解得到了板在一定厚度范围内变化所对应的色散曲线。通过分析钢板中相速度变化曲线,得出如下几个规律Lamb波在板中传播时,存在多个模式;当板厚确定时,频率越高,存在的模式将越多;当频率一定时,板的厚度增加,各个模式之间将越密集。更多还原

【Abstract】 In order to provide a theory basis for the experiment of mass level measurement, this paper sees the experiment equipment as the object, and makes some simplification. Then this paper adapts wave theory and corresponding boundary conditions, and deduces the dispersion equations of Lamb waves in a plate. By solving the dispersion equations the dispersion curves are obtained with the change of the plate thickness. Analyzing the change of phase velocity in a steel plate, some laws are got: when Lamb waves propagate in a plate, many modes exist in it; when the plate thickness is changeless, the higher the frequency is, the more modes there are in the plate; when the frequency is changeless, the thicker the plate is, the closeer the modes are.更多还原