Research On Structural Finite Element And Fatigue Reliability Analysis Of The Switch Beam In Light Rail

With the popularization of the monorail traffic in city of china, the security of themonorail traffic becomes more and more important. The switch beam which is one ofthe basic components in monorail traffic plays an important role to ensure the normaloperation of the train. Switch beam is different from the general reinforced concretebridges. It essentially belongs to the large welded steel structure. The switch beam thatthe paper studied belongs to joint five switch beam. Its working environment is complexand its working frequency is high. Getting the stress distribution and accurateunderstanding of the weak position to determine its reliability by using the engineeringanalysis software is very necessary and feasible. In this paper, the finite elementanalysis of the switch beam has been studied, and the fatigue life of the switch beam hasalso been analyzed. We hope the above work can provide useful reference foroptimization design of the switch beam.As the research object, the finite element model of the3rd section of the joint fiveswitch beam in Chongqing city has been established by using UG soft ware. Accordingto the actual operation of the switch beam, three kinds of loading scheme have beenidentified. The static analysis and modal analysis of the model has also been studied bythe ANSYS Workbench module. At the same time, the static strength of the secondbeam and other important components has also been checked. The fatigue life of theswitch beam is computed based on the random load spectrum. At the last, the reliabilityof the calculation results is given.The analysis results displayed that the static strength of the switch beam meets theuse requirements and have a larger margin. Maximum deformation is in the upper beam,even considering the vibration, the deformation is also acceptable. But there are obviousstress concentration point occurred in the welding position. The second beam, T axisand the bolt group all meet the requirements of static strength.The model analysis results show that the natural frequency of the structure alongwith the application of external load has a little change. The first mode frequency isalways around51Hz. The vibration deformation and the static strength deformationcoincidence, it needs to strengthen rigidity. Fatigue life prediction results show that the fatigue life coincide the requirementsof steel structure design. In the choice of the S-N curve of high reliability as the fatigueproperty of material, the fatigue life of switch beam is reduced, but the change is little.At the end the confidence of the fatigue life has been calculated, and found that the localoptimization can increase the fatigue life of the switch beam.