| With the continuous improvement of my country’s modern comprehensive transportation system and the acceleration of the urbanization process,it is more and more important to strengthen the pedigree construction of my country’s standard subway trains.Stainless steel car body has always been the first choice for subway vehicles because of its good corrosion resistance and light weight.In this paper,the performance of a certain type of stainless steel car body is checked,and the structure is optimized on the basis of ensuring the safe operation of the car body,so as to make the car body structure more reasonable,and provide a certain sense of guidance for actual production.This paper studies from the following four steps:1.This paper firstly introduces the development history and current situation of stainless steel car body at home and abroad,and expounds the research status of structural optimization.Then,the finite element analysis method and principle are briefly summarized.Taking a certain type of stainless steel car body as an example,the selection of finite element modeling unit and the related research on the modeling method of spot welding unit are carried out,and the finite element model of the car body is established.2.Load and calculate the static strength and fatigue strength of the vehicle body according to the EN12663 standard.Structural optimization and improvement are carried out on the position of unqualified strength,so that the static strength,stiffness and maintenance mode of the car body structure can meet the requirements of relevant standards.Then,according to the calculation results of the fatigue strength of the car body,the spot welding spot with the larger first principal stress is selected for mesh refinement processing,and the Weld-Fatigue software based on the equivalent structural stress method is used to calculate the fatigue life of the spot welded structure,and then verify Whether the fatigue strength of the car body meets the standard requirements.3.Use the OptiStruct solver to optimize the layout of the sidewall solder joints.Firstly,the stress of the side wall sub-model is checked to verify the feasibility of the sub-model method.Then,based on the topology optimization method of the variable density method,an optimization model with different constraints is constructed and solved,and the optimization results are compared to find out the solder joints on the non-main force transmission path.On this basis,further topology optimization is carried out on the layout of the side wall window solder joints,and the optimization method for the optimal arrangement of the solder joints on the main force transmission path is obtained,which makes the optimization scheme of the side wall solder joint layout more reasonable.The final optimization scheme reduces the number of side wall welding points by 17.25%,and the vehicle body performance parameters before and after optimization are compared to verify the feasibility of the optimization scheme.4.On the basis of the optimized model of the side wall solder joint layout,the size of the roof beam is optimized,the roof sub-model is established,and the thickness of the roof beam is selected as the design variable for optimization.The optimization result is 7.73% lighter than the original plan,compared with the performance parameters of the car body before optimization.The comparison results show that the optimized car body model still meets the performance requirements. |
PDF Full Text Request