Sensor/actuator optimal design for active vibration control of shell structure

In this paper, a method based on finite element technique is developed for the design of sensor/actuator system of the active vibration control of shell structure. To prevent the adverse effect of spillover, distributed modal sensor/actuator system is established using PVDF film. Although shell structure is three-dimensional structure, the PVDF sensor/actuator system can be treated as two-dimensional. The electrode patterns and lamination angle of PVDF sensor/actuator are optimized to design the modal sensor/actuator system. Finite element programs are developed to consider curved structures having PVDF modal sensor/actuator. The nice-node shell element with five nodal degree of freedoms is used for finite element discretization. Electrode patterns and lamination angles of PVDF sensor/actuator are optimized using genetic algorithm. Sensor is designed to minimize the observation spillover, and actuator is designed to minimize the system energy of the control modes under a given initial condition. Modal sensor/actuator for the first and second modes of singly curved cantilevered shell structure are designed using above mentioned methods. For the demonstration, numerical simulation of the closed loop system is performed. Discrete LQG method is used as a control law.