Study On Topology Optimization Of Stainless Steel Spot Welding Truck With Static And Dynamic Multi-objective

With the improvement of economic level,China’s railway traffic has developed rapidly.Safe and fast EMU trains become the popular choice for passengers on their travels and they have a promising development prospect.CAE technology can shorten the design cycle effectively,save the preliminary test cost,avoid production waste,and ensure the safety of products to a large extent.At present,At present,CAE technology is widely used by engineers in the development and design of rail vehicles.In this paper,the static and dynamic multi-objective topology optimization of weld spot on the stainless steel spot weld EMU Pullman vehicle body is studied based on the results of finite element analysis.Contents of this paper are as follows:(1)Determine the type of spot weld element and establish the finite element model.Five types of element are selected to simulate spot weld,the type of spot weld element is determined by comparing and analyzing the results of modal simulation and test.According to the basic principles of modeling and the basic process of modeling,the finite element model of vehicle body is established,which lays the foundation for subsequent calculation,analysis and optimization design.(2)Analyze the static and dynamic performance of the vehicle body.According to the relevant regulations of JIS E7106-2006 and the design requirements of the vehicle body,the stiffness and static strength of the vehicle body are analyzed and calculated by finite element analysis and check.According to the TB/T3115-2005 standard,the unconstrained free modal analysis of the vehicle body is carried out.The comprehensive displacement neutrographic and the first order vertical bending vibration mode are obtained.It provides data reference and guarantee for the follow-up optimization research.(3)Analyze and evaluate the static strength of the spot weld of the vehicle body.According to the BSEN 15085-3-2007 standard,the static strength of the spot weld of the vehicle body is analyzed and evaluated.It is determined that the calculation of the static strength of the spot weld of the vehicle body meets the design requirements and there is a large space for optimization,which lays the foundation for the next optimization of the spot weld.(4)Establish the model of spot weld topology optimization considering static and dynamic multi-objective.The basic idea of variable density method in topology optimization and the three elements of multi-objective topology optimization mathematical model are introduced.Using analytic hierarchy process to determine the weight coefficient,taken compromise programming method to establish a static and dynamic multi-objective topology optimization mathematical model of the stainless steel spot welding train.(5)Multi-objective topology optimization is carried out for the spot weld of the vehicle body.Based on SIMP model of variable density method,Opti Struct is used to optimize the spot weld,and the results of optimization calculation are analyzed,which determine the optimized spot weld layout.The static and dynamic performance of the vehicle body and the static strength of the spot weld is checked again,and compared with that before optimization,The results show that the number of spot weld is decreased by about 32.82% of the original design variables,and can meet the design requirements of vehicle body stiffness and static strength as well as static strength of spot weld.