Theoretical Resrarch Of Acuator Optimal Design Of Active Control On Cylindrical Shells Structure

Drastically vibrations which can cause structural damage or destruction, tend to happen when cylindrical shells structures are in outside incentive load. Appling intelligent materials into architectural structure to carry out active vibration control, which can effectively reduce the vibration and damage accumulation as well as improve the structure performance of safety. Compared with passive and semi-active control technology, active control technology is more flexible, more intelligent, more efficient and stronger adaptability. Base on the GMM’s magnetic characteristics, a GMM actuator which used for active control technology is designed. This paper discusses the optimal placement method of actuator in the cylindrical shells structure and analysis the corresponding verification. Main tasks are as followes:(1) This thesis studies the GMM’s magnetostrictive mechanism and the factors which influent the working performance, the factors includes stress, magnetic field, temperature and so on. For GMM as the core components, a new more efficient GMM actuator is designed, meanwhile through the magnetics properties test of GMM actuator. Under different preloading stress, the relationship between output performance and current are analyzed. And the preloading stress which can guarantee the optimal output performance is found. The results indicate that the GMM actuator can satisfy the needs for active vibration control of the cylinder dome structures,(2) For the main stress and deformation characteristics of cylindrical shells structure, the active vibration control system’s composition, working principle, construction and integration methods is researched. Adopting finite element modeling method, the dynamic finite element equations of the cylindrical shells structure active vibration control is established. The assembly method of the dynamic equation’s various parameters is analyzed. Based on the modern control theory, the state space model for cylindrical shells structure is established, which provide the basis for active control theory.(3) Based on the purpose of improve actuator efficiency, the optimum arrangement criteria were determined and not depend on control gains, and the optimal objective function is writted by MATLAB. Appling the reduce method, according to the influence rate for objective function in the cases of GMM actuator decorated in different positions, the GMM actuator’s layout mode and position is optimated when the numbers is determined. An LQR active control algorithm procedure which is writted by the MATLAB is used to carry on the active control’s time-history analysis. The results verify that the reduce method used for optimize GMM actuator is effective and feasible.(4) Based on the genetic algorithm, the optimum arrangement of GMM actuators in the cylindrical shells structure is studied. The fitness function is writted by MATLAB, and the optimization is calculated by using GA toolbox. The results prove that using genetic algorithm optimize the actuator position is more accurate and more efficienttly than the reduce method, but also it can realize the integral structure optimization too.(5) Based on the optimization results with genetic algorithm, the dynamic process analysis of cylindrical shells structures is done by LQR active control algorithm. By comparing the control performance and safety coefficient in different conditions, The effectiveness of genetic algorithm to actuator layout optimization is verified...