Research On Non-contact Active Control Of Photransfer Laminated Structures

With the rapid development of science and technology,especially in the field of Aeronautics and Astronautics,the complexity of the structures in these fields is increasing,and the performance of the system structures is also put forward higher requirements.Traditional electromagnetic excitation intelligent materials which were used in structural active vibration control,need additional electromagnetic excitation equipments and wire connections which were used to transimit energy sources and control signals,vulnerable to the interference of external electromagnetic field,impact the accuracy of control signal transmission and real-time performance.The new smart material,lanthanum modified lead zirconate titanate(PLZT)actuators under the uniform illumination of external high-intensity light will exhibit large photostriction and superposition phenomenon of photovoltaic and piezoelectric effect.Meanwhile along the direction of its polarization to produce a certain stress and strain,so the PLZT can directly transform light energy into mechanical energy and is not affected by electromagnetic fields and complex excitation equipments,and the application of PLZT photostrictive actuators in the active vibration control of laminated structures has a good development prospect.The following several aspects of the research work have mainly been completed in the paper:(1)The basic characteristic of the PLZT actuators and control application in classification of common configuration,including its working mechanism are introduced in the first part of dissertation.And the constitutive equations of the PLZT actuators in view of light-thermal-elastic-electric coupling are established.(2)The modal of the simply supported plate laminated photostrictive actuators is established.An optimization algorithm for the layout of the photostrictive actuators for active vibration control of the plate is proposed by the GA method.The effects of different distribution modes on the vibration control of laminated simply plate under the irradiation of constant light is analyzed.The simulation results show that the optimized distribution of the PLZT actuator has a more obvious effect on the modal vibration control of the simply supported plate.(3)The modal of the cantilever beam laminated photostrictive actuators and its modal vibration control equatonsis are introduced by using modal analysis,and using the finite element method to optimize the PLZT actuators distribution position.The control effect of vibration modes of the cantilever beam under irradiation of constant/variable light intensity is compared.The simulation results show that the finite element model analysis of the beam is correct and efficient,meanwhile chosing the appropriate light intensity could effectively improve the effect of active vibration control.(4)In order to realize the multi-modal vibration control of the simply supported plate in this thesis,the fuzzy neural network controller based on RBF network model is designed,and the sliding mode control method is used to design the first-level sliding mode function and the second-level sliding mode function with multi-controlled mode displacement and its modal velocity as variables.The fuzzy neural network active controller not only uses the sliding mode control method to transform the multi-modal control into the single modal control problem,also has the online learning ability of fuzzy rules and memebership functions.Meanwhile the system simulation results show that the fuzzy neural network controller is effective and feasible,and it can realize the multi-mode vibraton active control of the PLZT laminated simply supported plate structure.