Finite Element Analysis And Optimization Of Double Track Flaw Detection Vehicle Structure

For the problems of high speed and low detection rate of large-scale railway flaw detection vehicles and low efficiency reflected in high detection rate and low speed of smallscale flaw detection vehicles,a lighter,modularized and rationalized double-track flaw detection vehicle is studied and designed,in accordance with the technical specification for double-track flaw detection vehicles of Railway Head Office.It's of great significance to the development of railway maintenance operations.Firstly,this paper analyses the current research situation at home and abroad,refers to the most advanced research results and technologies at home and abroad,designs the overall structure of the double-track flaw detection trolley according to the technical specifications of the Railway Corporation,uses Solid works 2016 software to carry out the overall design of three-dimensional modeling,and through reasonable simplification,chooses shell element and solid element to establish the limited calculation.Metamodel.In the process of modeling,not only the treatment and simplification of boundary conditions are considered,but also the treatment of different mass and load in the body structure is studied and analyzed in detail.Combining with the actual running environment of the car,the static analysis and calculation of the bearing structure of the lower chassis are carried out by using Ansys Workbench 16.2 to understand the strength,stress,deformation and safety factor of the body structure,so as to further understand the situation of the strength,stress,deformation and safety factor of the body structure.To improve the strength and performance of the body structure,based on the analysis results,through finite element analysis and calculation,the defects of the undercarriage load-bearing structure are studied.It is found that the safety factor is only 1.02,which can not meet the performance index,so the cross-section form of the load-bearing structure needs to be changed.In this paper,four different sections of the lower chassis bearing structure are analyzed by finite element method.By comparing the data of finite element analysis,the optimal section is selected to improve the safety factor of the lower chassis bearing structure.According to the selection of the best section profile,two different lower chassis loadbearing frame structures are constructed.By importing the model into Ansys Workbench 16.2,contact treatment,meshing,load loading and so on are carried out,and the results of two different displacements,stresses,weights and safety factors of the lower chassis loadbearing frame structure are calculated.Through the finite element analysis of the lower chassis bearing structure,it is concluded that the stress distribution,displacement distribution,weight and safety factor of the second type of chassis bearing frame structure are more reasonable,especially the safety factor increases from 1.02 to 3.22,and the weight decreases from 15.26 kg to 14.58 kg.Secondly,aiming at the problems found in the use of the rear axle structure of the double-track flaw detection car,the finite element analysis and calculation of the rear axle structure of the car are carried out through the steps of modeling,introducing the model into Ansys Workbench 16.2,setting the boundary conditions,meshing,loading and so on.From the finite element analysis results of the rear axle structure,it can be seen that the stress distribution of the rear axle is unreasonable and there are stresses.Concentration and low safety factor defects,the safety factor is only 2.02,the weight is 8.8kg,the displacement change of rear axle is too large,and the displacement change of rear axle is different from that of frame back beam.All these indicate that the design of rear axle structure is unreasonable,and the structure has defects,which leads to the phenomenon of broken axle in the course of using the rear axle.It is necessary to optimize the design of the rear axle structure.In this paper,three different types of rear axle design structures are proposed.By comparing the advantages and disadvantages of the three types of rear axle structures,the reasonable design scheme of rear axle structure is determined to be a half-axle design scheme.The finite element analysis and calculation of the rear axle structure of the scheme are carried out.The stress distribution,displacement variation,weight,safety factor and other performance indicators of the rear axle scheme are obtained.The performance indicators are much better than those of the original rear axle.The scheme,especially the safety factor,increased from 2.02 to 2.56,and the weight decreased from 8.8 kg to 8.06 kg.Tests and field tests show that the designed rear axle structure is more reasonable,more scientific,more convenient and lower cost.Through the above research,the finite element model of the lower chassis bearing structure and the rear axle structure established in this paper is reasonable,and the finite element analysis is correct.The optimized design scheme and structural form can also provide design ideas and guiding significance for the design and manufacture of similar convenient flaw detection mechanical equipment during the production and manufacture of the direct flaw detection vehicle.