Damper Optimization And Seismic Control Analysis Of Large-span Latticed Truss Structure Based On Improved Genetic Algorithm

The large-span latticed truss structure is light weight,high strength,spacious,simple and elegant architectural form,which is widely used in crowd ed public places such as stations,airports,stadiums and exhibition halls.However,it will generate great vibration that resulting in structural damage or even collapse when subjected to seismic or other dynamic excitations due to its small stiffness and low damping.Viscous damper has good performance in damping control and is less sensitive to temperature and excitation frequency,with the property of simple structure and easy construction.Based on above background,in order to study the seismic contro l performance of the large-span space damping system with viscous dampers which are used to replace structure bars,this paper compiles an improved optimization program combining with the existing optimization of viscous dampers and Genetic Algorithm.In addition,it studies the optimization of locations and numbers and other influencing factors of viscous dampers,and compares the capacity of seismic control under the influence of frequent and rare seismic.The main contents of this paper are as follows:(1)First of all,we introduce the basic properties of viscous damper and describe the seismic control principle of viscous damping system based on truss structure.Meanwhile,the method applied to seismic control of large-span latticed truss structure are summarized.(2)On the basis of existing damper optimization study of large-span latticed truss structure and taking the percentage of modal strain energy of replaced bars as optimized method,an improved operation adaptive Genetic Algorithm optimization program is complied,which is used to optimize viscous damper.(3)An example is given to analyze large-span latticed truss stadium structure.The dampers in the structure are optimized by the improved Genetic Algorithm optimization program.In order to verify the validity of the optimization program,the displacement and acceleration damping effect of optimized layout solution are comparied with random layout solution under frequent seismic.(4)For further study of viscous damper optimization in large-span latticed truss structure under frequent seismic,the optimal optimization case of location and number and damping coefficient of viscous damper is finally determined and the rule of optimal dampers location is summarized.(5)Based on the study of frequent seismic,this paper further discusses the seismic control capacity of the optimal optimization case on large-span latticed truss structure under rare seismic by comparing and analyzing the peak values of nodes displacement and acceleration,stress amplitude of bars,force and displacement of viscous dampers.Whether it is under frequent or rare seismic,the optimal optimization case complied by the improved Genetic Algorithm optimization program can effectively reduce the displacement and acceleration peak val ue of each direction of nodes on large-span latticed truss structure.Under rare seismic,the hysteresis curves of the viscous dampers are all full,which shows that the structure can absorb much energy.Therefore,the viscous dampers can greatly reduce t he stress amplitude of bars to keep the structure components in an elastic state and improve the stress state of the structure.This paper provides the reference value for application and design of viscous dampers on large-span latticed truss structure.