The Aseismic Optimum Design Of The Structure With Viscosity Dampers Based On Genetic Algorithm

The passive control of the damping structure of energy dissipation, thedamping effect of viscous dampers mostly depends on the installation quantity and theposition. If the number of dampers was certain and the layout of dampers wasreasonable, not only can reduce the cost, also can obtain good vibration control effect,so it was necessary to study the optimization of damper position.The key of the optimization of damper position was to realize the objectivefunction. Due to the randomness of the earthquake, the optimization based on randomvibration theory don’t have the reality. Because of the shortcoming, the optimizationof damper position based on response spectrum was used in this paper. According tothe objective function based on response spectrum, it was advantageous for thepractical engineering application.Genetic algorithm and direct search toolbox in MATLAB software wasadopted to this paper. If the number of dampers was certain, the position of damperwas certain once time. The calculation was simple and feasible, also makes thegenetic algorithm well combined with damping structure optimization design.The random earthquake response of dissipation structure with Maxwellviscous dampers and the location optimum method of viscous dampers was studied．According to the relaxation time of the viscous dampers in practicalengineering, the random seismic response of the single degree and the two degrees ofthe freedom system of Maxwell viscous damping energy dissipation structure areanalyzed. By establishing the motion of structural equation, the dynamic response ofstructure were analyzed, the variance of the displacement response of the structurewas approximately calculated, the results were compared with the accurate value andthe modal strain energy, the example showed that this method could be used for thevariance of the displacement response of the structure and the results error was in thepermit scope and the calculation was more simple.The location optimum method of the viscous dampers was studied. Choose thereinforced concrete frame structure as an example, because of the reality of therandomicity of earthquake, for the convenience of application in practical engineering,the optimization design of this paper was based on response spectrum. After thereasonable determination of the objective function based on response spectrum,according to the damper number were known, an example was given to testify themethod in comparison with different objective functions by using direct searchmethods of genetic algorithm toolbox in MATLAB software to search the location optimum method of the viscous dampers directly on each layer of structure and tocalculate the displacement between the layers，the maximum displacement and thehorizontal seismic force response of each layer. The numerical calculation showedthat, for low level structure, this paper recommended the objective function1, theangle of relative interlayer displacement, for the high-rise structure, this paperrecommended the objective function1, the relative value of the displacement betweenthe layer and, these showed that this optimization method could be applied to thelocation optimum of viscous dampers, it was simple、feasible and could have a verygood effect.