Trapped Scholte modes supported by soft elastic cylindrical rods underwater

This paper documents trapped Scholte modes; nonradiative surface acoustic modes that exist on fluid-loaded elastic cylindrical rods. Unlike previously reported surfacelike waves on cylindrical rods, the Scholte modes identified here are localized to the interface between the rod and the surrounding fluid. The study investigates plastic rods submerged in water, which allows exploration of the domain where the Scholte velocity is significantly slower than the speed of sound in water. The supported Scholte modes are shown to become increasingly localized to the solid-fluid interface at high frequencies, as their phase velocities tend toward that of the Scholte wave on a planar interface. This was modeled numerically using the finite element method and experimentally verified using cast acrylic rods underwater.