Application Of Magneto-Rheological Damper In Large-scale Structure Dynamic Control

Magneto-Rheological(MR) fluid is a kind of smart material got great development in recent years.MR dampers are continuously adjustable damping,wide dynamic range,fast response and low power consumption which can be made the semi-active vibration isolation systems as required.Because of complex nonlinear damping characteristic of MR damper,the dynamic description of the current model and the requirements of real-time control are the key researches.To establish effective realtime control strategy in vibration isolation system is another key research.MR damping system applied to the study of structure is still in its early stages.Thus the MR damping system control strategy and application research has great significance.This dissertation pays more attentions on the use of theoretical analysis and numerical simulation approach and finite element analysis are conducted to characterize the dynamical performance of the MR damper and vibration damping control algorithm for the design and implementation of research.With modern control theory to establish the practical application of appropriate control strategy which can be applied to roof trusses,large space structures under external excitation of the semi-active control.The more detailed researches are follows:(1) Analysis and comparison of the magneto-rheological damper mathematical model. Reference to the related experimental data,it presents a more accurate and practical the equivalent stiffness and damping models.In addition,the operational effects,such as the magnitude of voltage,the amplitude and frequency of excitation,on the parameters of the models are discussed.Provide a reference of MR damping system design and performance prediction.(2) The dynamic analysis of MR damping system and researches on the control strategy. Accroding to the characteristics of MR damper,it establishes the model based on magneto-rheological damper vibration control system and comparison of dynamic characteristics for different structures of the damping system.Research on the application and the use of the equivalent linear model of MR damper combined with the characteristics of damping system.With the application of modern control and feedback control theory,the control strategies based on acceleration and velocity feedbacks are put forwards.Through the amplitude-frequency characteristics theory analysis and numerical simulation,the results verify the feasibility of the control strategy.(3) Establish state space model of the controlled system and analysis structure of the construction under the semi-active control by use of optimal control strategy and the control strategies based on acceleration and velocity feedbacks.Simplify f'mite element structural analysis model to compare the transient dynamic response of uncontrol and control structure and verify the feasibility and effectiveness of the control system and strategy.