Piezo Actuated Vibration and Flutter Control

The potential application of smart materials is being investigated by various researchers in the perspective of building intelligent systems. A smart structure consists of distributed actuators and sensors with associated processors to analyse and control the structure. Piezoceramics, magnetostrictive materials, electro-rheological fluids, magneto-rheotogical fluids, shape memory alloys, fibre optics are quite often used in realising a smart/intelligent system. In this paper, vibration and flutter control using piezoceramics is reviewed. Various aspects covering relative merits of piezoceramics with other smart materials and application capabilities are discussed

Form factors for vibration control of beams using resistively shunted piezoceramics

The present work is motivated by a desire to investigate the effect of thickness and length ratios of the resistively shunted piezoceramic-host beam system on its ability to induce damping. Are there any optimal length and thickness ratios for which the additive damping due to piezoceramic resistive shunting is a maximum? Are these thickness and length ratios influenced by the boundary condition

Closed-loop flutter control using strain actuation

The present work investigates feedback control of flutter using piezoceramic strain actuators. A two degree-of-freedom oscillating airfoil model with the air loads simulated assuming unsteady aerodynamics is considered. Various feedback measurement combinations for SISO feedback control and strain actuation in the heave and pitch direction are studied to quantify their effect on flutter. The effect of sensor placement on the airfoil, for combined pitch and heave measurement feedback, is also studied. The results show that for a given aeroelastic system, sensor location is an important parameter in realizing an increase in the flutter speed. It is demonstrated that the flutter speed can be increased by more than 50% through strain actuation in the pitch direction

Structural vibration control using resistively shunted piezoceramics

Application of piezoceramic materials in actuation and sensing of vibration is of current interest. Potential and more popular applications of piezoceramics are probably in the field of active vibration control. However, the objective of this work is to investigate the effect of shunted piezoceramics as passive vibration control devices when bonded to a host structure. Resistive shunting of a piezoceramic bonded to a cantilevered duralumin beam has been investigated. The piezoceramic is connected in parallel to an electrical network comprising of resistors and inductors. The piezoceramic is a capacitor that stores and discharges electrical energy that is transformed from the mechanical motion of the structure to which it is bonded. A resistor across the piezoceramic would be termed as a resistively shunted piezoceramic. Similarly, an inductor across the piezoceramic is termed as a resonantly shunted piezoceramic. In this study, the effect of resistive shunting on the nature of damping enhancement to the host structure has been investigated. Analytical studies are presented along with experimental results

Resonantly shunted piezoelectric layers as passive vibration control devices

The effect of resonant shunting on the vibration behaviour of a duralumin cantilever beam is experimentally investigated with reference to the reduction of response amplitude and additive damping and the change in resonance frequency. The overall reduction in tip amplitude is around 4% for a peizoceramic layer with electromechanical coupling coefficient (k31) equal to 0.30. However, higher values (k31 = 0.36, typically applied in beams and rods) of electromechanical coupling coefficient result in significantly higher levels of reduction of vibration amplitude with a change in natural frequency from short circuit to open circuit value. A 20-30% reduction in response amplitude and 8-10% change in natural frequency (open circuit to short circuit) is possible when the planar electromechanical coupling coefficient (kp, typically applied in discs and plates) is 0.6-0.65