Introduction

Distributed control of vibrating structural systems like beams and plates have been studied since the beginning of the ' 80s. The major application of this concept was in terms of control of trajectory in slender aero-space structures like rockets and missiles by controlling the thrusts from the jets. The stability margins for such systems while subjected to distributed follower force tangential to the deformed body have been obtained. With the advent of smart materials, these theoretical results have gained more practical utility as truly distributed sensing and actuation layers have been developed from smart materials. Piezoelectric polymers like Polyvinylidene Fluoride (PVDF) are quite compliant and could be applied in patches over any curved surface. Burke and Hubbard have designed PVDF film based distributed actuator and sensor for vibration attenuation in beams and plates [ ].

The technique is known as spatial shading in which bi-axial PVDF films are placed in ramp configuration to develop a single all-mode vibration controller.

Figure 27.1: Distributed control using piezoelectric film