Research And Application Of Alignment Calculation Of Suspension Bridge Based On Particle Swarm Optimization Algorithm

Suspension bridges are widely used both at home and abroad in recent years due to their attractive design,simple construction,clear stress relationship,high material utilization and large span.Suspension bridge is a flexible structure with strong non-linear characteristics,and this paper focuses on the analysis of the main cable shape of the suspension bridge.Main cable is the basis of structural calculation of suspension bridge,and its shape will also directly affect the stress of the whole bridge structure.Accurate calculation and analysis of main cable alignment and precise setting of saddle position are prerequisites for achieving ideal bridge state,so the main cable alignment must be accurately controlled in the design process.The alignment of suspension bridges can not be adjusted by the stress conditions at later stage,and the entire construction process must be controlled by accurate calculation.Solving the linearity of suspension bridge requires solving the non-linear equation group in the calculation theoretical analysis,which is difficult to obtain directly by ordinary analytical method due to its complexity.Therefore,this paper adopts particle swarm algorithm,one of the popular algorithms at present,to solve the non-linear equation group involved in the linearity calculation of suspension bridge,so as to meet the actual needs of engineering.The main research work of this paper is as follows:(1)Several calculation theories of suspension bridge are elaborated in detail.Main cable shape analysis methods and saddle location calculation methods such as parabola method,sectional catenary method and finite element method are analyzed in depth.From the shape of main cable to the setting of saddle,the calculation of the shape of main cable of suspension bridge is systematically analyzed.(2)Particle Swarm Optimization(PSO)is elaborated in detail,and the advantages and disadvantages of different improved PSO are analyzed.Particle Swarm Optimization(PSO)with inertia weight is selected to solve the problem by combining the main cable characteristics of suspension bridge.In order to prove the excellent performance of particle swarm optimization(PSO)and the superiority of the selected PSO with inertia weight,two test functions of the selected PSO are calculated and analyzed.It is found that the selected PSO with inertia weight can converge to the optimal value more quickly and can be selected as the calculation method to solve the non-linear equation group of suspension bridge.(3)Taking a anchored Changjiang suspension bridge as engineering background,particle swarm optimization algorithm is used to solve the main cable shape of the bridge and the arrangement position of main cable saddle and loose cable saddle of the bridge.Because the calculation of main cable of suspension bridge is heavy and complicated,the calculation program is compiled and solved by MATLAB software.Finally,the calculated value analyzed by finite element analysis software is compared with that calculated by particle swarm optimization algorithm.By comparison,it is verified that the calculation results of particle swarm optimization algorithm are almost the same as those of finite element method,and that the results of particle swarm optimization algorithm are correct,and it is more efficient than that of finite element software modeling,which has certain engineering application value.