Study On The Experiment And Applications Of Stochastic Response And Optimal Control Of Nonlinear Systems Based On Stochastic Averaging Method

The present dissertation studies subjects which include nonlinear stochastic response of damaged structure based on stochastic averaging method,nonlinear stochastic optimal control with experimental validation and nonlinear stochastic optimal delayed control and it's experimental validation.The first chapter summarizes the progress on nonlinear stochastic opticmal control and delayed opticmal control.The second chapter studies nonlinear stochastic vibration of bridge with breathing crack under stochastic traffic loading. The probability density of bridge strain response depends on the structure damage extent.The third chapter studies nonlinear stochastic optimal control of partially observable linear structures. For cantilever beam equipped with piezoelectric actuator control devices and sensors under horizontal ground acceleration excitation, it is shown that this nonlinear stochastic optimal control strategy is better than classic LQG control strategy, and the experimental results verify this conclusion. In the fourth chapter the control actuator with delay characteristics is studied. A complete-period time-delay compensation method for time-delayed stochastic optimal control is proposed.For a flexible cantilever beam under stochastic excitation, numerical simulation and experimental verifies the proposed compensation method. In fifth chapter experiment verifies that nonlinear stochastic optimal control and delay compensation control strategy are suitable to vibration control for more complex 3-floor frame structure under stochastic load. In the sixth chapter the mathematical modeling,model testing and parameter identification and control strategy designing for large-scalellflagllgate in Suzhou river are given.In the last chapter some conclusions about nonlinear stochastic optimal control experimental validation are drawn and further researches needed are pointed out.