This paper introduces a model for a vibration control system in which spatially etched polyvinylidene fluoride (PVDF) was utilized to implement uniform damping control on a distributed system. Uniform damping node control (UDNC) theory states that near optimal vibration control can be achieved when the following criteria are met: all modes are damped at the same exponential decay rate, the open-loop and closed-loop natural frequencies of the structure are identical and the closed-loop modal shapes are identical to the open-loop modal shapes. To help accomplish this, in a system with N modes participating in a response, sensor/actuator pairs are placed at the nodes of the N + 1 modes. Spatially shaded PVDF actuators are distributed actuators that produce pseudo-discrete forces due to the special weighting applied to the etched electrodes. The system was demonstrated using a spring steel cantilevered beam and spatially etched PVDF actuators that were placed according to nodal control theory. When given the set of gains that are attributed to UDNC, the modes de-couple, reducing spillover. This experiment marks the first time that uniform damping control has been realized experimentally.

In this research, the design of a piezoelectric point actuated active aperture antenna is introduced. The antenna consists of numerous piezoelectric point actuators placed perpendicular to the doubly curved aperture. The point actuators are comprised of a piezoelectric element and a stick-slip mechanism used to generate motion. A specially designed code that takes into account the mechanical and electromagnetic effects is used to determine the desired shape of the aperture. The final shape of the aperture is verified using stereo photogrammetry.