Active Vibration Control Of Space Plate And Shell Structure Based On Hybrid Photovoltaic/piezoelectric Actuation Mechanism

Applying smart structure to vibration control of spatial plate and shell structure has already become a new research hotpots. In this paper, lanthanum modified lead zirconate titanate(PLZT) is combined with piezoelectric actuators. Combining the merits of remote and non-contact control and high voltage production of PLZT with the high response speed of piezoelectric actuators, a new method for hybrid photovoltaic/piezoelectric actuation mechanism is proposed. The hybrid photovoltaic/piezoelectric actuation mechanism is employed to study the active vibration control of spatial plate and shell structure. Thus a new method for vibration control of spacecraft plate and shell structure is provided.Based on the study of the voltage producing mechanism of PLZT, the equivalent circuit model corresponding to the hybrid photovoltaic/piezoelectric actuation mechanism is developed, and the mathematical expressions of driving voltage and strain of actuator are derived. Then the experimental platform is established to study the hysteresis of hybrid photovoltaic/piezoelectric actuation mechanism. By comparing and analysis, it is experimentally proved that the control method employing hybrid photovoltaic/piezoelectric actuation mechanism is valid in solving the problem of PLZT strain hysteresis.The influence factors of hybrid photovoltaic/piezoelectric actuation mechanism are explored with the hysteresis analysis experimental platform. The influences of light intensity and piezoelectric actuator electrode surface area a nd thickness on the actuation voltages of piezoelectric actuator are investigated. And the relations are deduced between the electrode surface area, thickness of piezoelectric actuator and equivalent resistance. Meanwhile, the validity of hybrid photovoltaic/piezoelectric actuation mechanism mathematical model is verified under different light intensity conditions.The location and geometrical parameters of piezoelectric actuators have a great influence on its driving forces. To determine the optimal config uration parameters of piezoelectric actuators, the open cylindrical shell is employed as the research object. The dynamitic model of laminate structure is developed, and then the modal analysis is conducted. The optimization method of actuator configuration parameters is studied with the criterion of the maximization of the modal control force.The actuation strategy with multiple driving pieces of PLZT is studied to overcome the shortcoming that photovoltage produced by PLZT is limited by the restricted polarization length, and to improve the response speed of the voltage. By employing the logical switch circuit, piezoelectric actuators can receive relatively high initial voltage by ON-OFF control. Positive/negative connection between PLZT and piezoelectric actuators can be accomplished within a single cycle to realize full cycle control. When two pieces of PLZT are respectively connected to the piezoelectric actuator positively and negatively, charge loss can be reduced. Finally, through the experiments of active vibration control of cantilever beam, the validity of the hybrid photovoltaic/piezoelectric actuation mechanism is verified.Aiming at the vibration control problem of spatial plate and shell structure, a new control method with hybrid photovoltaic/piezoelectric actuation mechanism is proposed. The basic theory of the mechanism is studied in detail and the superiority of the mechanism on vibration control is verified. Then a fresh thought is provided with the application of smart structure to the fi eld of spatial plate and shell structure vibration control.