The Semi-active Optimal Control Research Based On Piezoelectric Friction

China is a country of Multi-shock, the long-term earthquake disasters in Chinaresulted in huge economic losses and casualties. How to reduce the impact ofearthquakes on human society is an important issue which should be solved in the fieldof engineering seismic. Structural vibration control is one of the methods whichcan reduce the impact of earthquakes on engineering structures. Structural vibrationcontrol is that the appropriate number of control devices are installed in specific localof the buildings. When the earthquake is coming, the control devices and structureswill absorb the seismic energy together in order to reduce the seismic response of thestructure. The structural vibration control has many types. The semi-active control bothhas the advantage of active control and passive control, so that it is popular to thenational engineering and technical personnel. With the rapid development of smartmaterials, it provide a new way for the realization of the structure of semi-activevibration control.In this paper, the main work is as follows,which based on the specialphysical and mechanical properties of the piezoelectric materials and the semi-activecontrol theory:(1) It uses ANSYS finite element analysis software to analyze the performance ofpiezoelectric ceramic tube displacement, output performance and the hysteresiseffect, compared with the factory properties, they are in good agreement, all thoseshowed that the model is more reasonable and reliable calculations. The same time,take the piezoelectric ceramic tube provided by the manufacturer as a prototype,using the inverse piezoelectric effect of piezoelectric materials, invent a new type of piezoelectric friction damper with works and construction methods, established theconstitutive equation under the harmonic loads, and gives the design configurationdetail. The analysis results show that the proposed friction damper can easily use theinverse piezoelectric effect of piezoelectric ceramic tube to change the mechanicalproperties of the damper, in order to achieve the semi-active control of structuralvibration.(2) It uses the ANSYS9.0Series software, established the finite element analysismodel of a space lattice structure, and studied the composition of the model structureof the calculation of semi-active control system and the corresponding controlprinciples, also the integrated approach. The same time, also using the finite elementmodeling approach, based on kinetic modeling of piezoelectric friction damper,established the semi-active control of the finite element dynamic equation for the spacelattice structure, and analyzed the formation process of the parameters, especially themass matrix, stiffness matrix, damping matrix and the control location matrix and soon. In addition, as the basis, described the semi-active control theory-OptimalBang-Bang control algorithm, determined the friction of piezoelectric friction damperaccording to the relationship between the active control and the structure of speedreaction, in order to achieve the structural vibration of semi-active control.(3)Based on the genetic algorithm of probability search features, studied theoptimized layout of piezoelectric friction damper in the space lattice structure,the main method is laid the dampers on the structure of bracing and integrated into thestructure. It use MATLAB software to write a fitness function program, and useGADS genetic algorithm toolbox for optimization, and identified the damper positionin the space lattice structure of the optimal layout under certain conditions with thenumber of dampers. Finally, considering the structure of the seismic reliability, controleffect, the hardware cost and other factors, initially identified the number of damperlayout, followed by MATLAB simulation analysis to explore the uncontrolled andcontrolled structure, the damper controlled structure of the random layout and Optimallayout,it come to general conclusions, and inspected the corresponding control results,and verified the feasibility and effectiveness of using the genetic algorithm to thelayout of piezoelectric friction damper. The results show that, under normal circumstances, when laid15damper, the control of the structural displacementresponse effect up to about50%, which showed visible control effect. In addition,under the same conditions as the number of dampers, it applied GADS geneticalgorithm toolbox to optimize the layout, the displacement response of its structuremore than10%effective than randomly layout.