Numerical analysis of wave propagation control using evanescent modes of Lamb waves

Abstract

Evanescent Lamb modes were numerically analyzed for controlling wave propagation in a structure consisting of a stacked plates and a bulk material such acoustic metamaterials as acoustic diodes. A single evanescent S1 mode of Lamb wave was generated by applying an external force distribution that is equivalent to the mode structure. It was confirmed that wave energy can propagate when structural change is located within the dominant area of the evanescent mode. This phenomenon was also seen for simple distribution of external force that models wave incidence with ultrasonic transducers, which shows that this can also be used for acoustic diode.