Propagation of lamb waves in 1-3 piezocomposites and their application to liquid sensors

This paper deals with the Lamb modes in 1-3 piezocomposites. The dispersion curves in the cases where the plate is free and loaded by water, as well as the electromechanical coupling factor for a piezocomposite with 36 % volume fraction of ceramic have been calculated It is found that the first antisymmetric mode has a very low coupling factor, whereas that of first symmetric mode has a high value. Experimental measurements of the phase velocity of the four lowest order modes of Lamb wave devices based on piezocomposites are found to be in fair agreement with theory. Furthermore, as predicted by theory, no significant attenuation of the first symmetric mode is observed when the plate is loaded by water.