Structure-borne traveling wave (SBTWs) have been investigated as means of propulsion and solid-state motion. Experimental studies have shown that SBTWs can be excited at various frequencies simultaneously by the superposition of the excitation signals. This paper examines superposition as a tool to improve the quality of SBTWs in targeted areas of a two-dimensional aluminum plate. Such waves are better suited for particle motion applications, where high quality SBTWs are required to exist on specific areas.
The superposition of SBTWs is investigated through the use of a Finite Element model which represents a thin plate with coupled-piezoelectric wafers and fixed boundary conditions. Superposition of excitation signals is then applied to combine two SBTWs: one with overall high quality but poor quality in a region of interest and one with high quality in this region of interest but with poor overall quality. The quality of the SBTW is evaluated using complex orthogonal decomposition (COD). The superimposed SBTWs are then tailored further by adjusting the relative amplitude of the two excitation signals. Tailoring SBTWs to be more prevalent in specific areas of the plate allows for high-quality waves in prescribed locations to be generated while maintaining the overall quality across the plate, without the need for a large number of actuators.