An Improved Method to Measure Slow Compressional Wave in Fluid-Saturated Porous Plates by Using Lamb Modes

Abstract

The theory of elastic wave propagation in fluid-saturated porous solids was established by Biot in 1956 [1,2]. Biot predicted the existence of three bulk modes: fast compressional wave, slow compressional wave, and shear wave. However, experimental confirmation of Biot’s theory at ultrasonic frequencies was not achieved until 1980 when Plona [3] observed slow compressional waves on fluid-saturated synthetic porous solids by using mode conversion technique. Since that time, Plona’s method has been adopted as a major approach to measure slow compressional wave in fluid-saturated porous media.