液—固密度比对漏Lamb波色散特性的影响

基于对液体载荷固体板中漏ｈａｍｂ波传播模复波谱的计算，研究了液—固密度比对漏Ｌａｍｂ波色散特性的影响．计算结果表明，当液体密度接近固体密度时，一般认为的漏Ｌａｍｂ波和自由界面的Ｌａｍｂ波色散曲线基本一致的假设是不正确的．增大液—固密度比将导致漏Ｌａｍｂ模之间的相互作用，并发生部分漏Ｌａｍｂ模的重合、互易和分离现象．当液体密度从极稀薄向极稠密交大时，漏Ｌａｍｂ波的色散曲线从自由界面的Ｌａｍｂ模向法向位移为零的滑移突持边界条件的情况过渡．

Influence of Fluid-to-Solid Density Ratio on Dispersion Characteristics of Leaky Lamb Modes

Based on the calculation of the complex wave spectrum of leaky Lamb waves in a fluidloaded solid plate, the influence of the ratio of fluid-to-solid density on the dispersion characteristics of the leaky tomb modes is studied. Numerical results of the dispersion curves show that generally accepted assumption of similarities for the dispersion curves between the Lamb modes and the leaky Lamb modes are not valid as the fluid density approaches that of the solid. Increasing the ratio of fluid-tosolid density leads to the interaction between these leaky Lamb modes and to mutual overlap, interchange and separation between portions of their branches. As the fluid density increases from very tenuous to very dense, the dispersion curves gradually changes from the Lamb wave to that of the plate with zero normal surface displacement.