A Pi shape piezoelectric actuator for vibration control application

A Π (Pi) shape piezoelectric actuator (PIPA) is proposed in order to make piezoelectric stack can be more conveniently mounted on beam or plate structure for vibration control applications. PIPA has flat bottom provides convenient mounting surface. It consists of two main components, a piezoelectric stack and a Pi shape pedestal. They are assembled together by a bolt which applies pre-compression load to the piezoelectric stack and makes the stack can be removed and replaced conveniently in practice. Equation about the relation between actuating moment of PIPA and driving voltage was derived. It was applied to the vibration control of a cantilevered beam. Thermal elasticity analogy method was used in the modeling of the cantilevered beam with PIPA mounted on its root surface. The state space model of this piezoelectric control system was established for vibration control system simulation. Linear quadric regulator (LQR) and neural network model predictive (NNP) control strategies were adopted respectively. Simulation results demonstrate that using PIPA with those control strategies the first bending mode amplitude of the beam can be suppressed by about 79% and 95%.