Smart structure vibration control using a new bending type of piezoelectric stack actuator

A new ∏(pi) shape piezoelectric stack actuator (PISA) was designed and applied to vibration control of a cantilevered beam. This new actuator consisted of a piezoelectric stack and a ∏ shape metal pedestal. They were assembled together by a screw providing a preload needed by the piezoelectric stack. The pedestal was designed to act as an external lever generating and transferring actuating moment to the structure. The pedestal made PISA be a bending type actuator. Its bottom provided a flat bonding surface for PISA in vibration control applications. The actuation moment of PISA was derived and then it was used in a vibration control system for a cantilevered beam. Positive position feedback (PPF) control and neural network predictive (NNP) control strategies were adopted to control the first bending mode vibration of the beam. Simulation results demonstrated that, the amplitude of the first bending mode of the cantilever beam could be suppressed by 92% using NNP control strategy, while using PPF control strategy the amplitude could be reduced by about 57%. The results demonstrated that the proposed PISA could serve as a high efficiency piezoelectric actuator in structure vibration control applications.