Spherical Reticulated Shell Structure Of The Numerical Simulation Of Wind Load And The Active Control Study

With the development of economic and social activities, people demand for large span reticulated shell is more and more big. However, due to the structure of the main use of lightweight, high strength building materials, structural stiffness decreases, and is more sensitive to wind load, under the action of wind load, it is easy to be destroyed, the wind vibration damage. So, need to understand the characteristics of long-span reticulated shell surrounding wind field, and in view of the wind load on the wind-induced vibration of long span reticulated shell to take active control method to reduce the damage. This article is based on spherical reticulated shell structure, through the fluid software FLUENT14.0 carries out numerical simulation of wind field around the structure, and in view of the wind load on the structure of the wind vibration response of the active control study, the main work is as follows:(1) The average wind expounds the nature and the basic characteristic of the fluctuating wind, and the numerical simulation of wind load a detailed overview of the basic theory of knowledge, through the fluid software FLUENT 14.0 wind field around the structure of the Steady state simulation(Steady), have a relatively stable flow field, the calculation results of the Steady state as the initial state of the Transient simulation(Transient), then use a large eddy simulation(LES) was carried out on the wind field around the structure of the Transient simulation, obtained the spherical reticulated shell of each node in the wind pressure, wind load behind for vibration control study provides a numerical basis.(2) According to the modern control theory, the basic concept and composition of active control system, a brief overview of the state space model of active control system is established, and the active control system of the actuator position matrix integration methods are discussed in this paper. Aiming at the condition of the structure are actuators with, write the linear quadratic optimal control(LQR) algorithm program, the wind vibration control of structures using MATLAB software has carried on the simulation analysis, the structure of each node in the displacement, velocity and acceleration control effect contrast figure, by comparing the control effect analysis: LQR active control algorithm for wind vibration response of the control effect is obvious, for the wind vibration control is a kind of feasible active control algorithm.(3) According to the optimal allocation of actuators, from two aspects of optimal allocation criterion and optimal allocation algorithm are analyzed in theory, and puts forward the optimization method based on genetic algorithm. Established the evaluation of wind vibration active control of the optimization performance index, and according to the performance index is constructed the corresponding fitness function, the use of MATLAB software's own genetic algorithm toolbox(GADS) optimized calculation to the position of the actuator. Through the analysis results show that with the increase of genetic algebra, fitness function value in convergence condition gradually, the position of the actuator gradually tends to the optimal solution, illustrates using genetic algorithm to optimize the location of the actuator is feasible.(4) Describes the weight matrix Q and R of linear quadratic optimal control(LQR), write the weight matrix Q?R, the optimization of objective function, using their own genetic algorithm toolbox in MATLAB software(GADS) the weight matrix Q?R, the optimization analysis. Based on the analysis results show that the actuator in meet the control limit cases, its control effect can meet the performance requirements.