| At present,the highly developed national economy,business trips and travel promote the flow of personnel to become more and more commonplace.People are more in pursuit of comfortable,convenient and efficient modes of travel which rail transportation with these remarkable advantages are becoming the preferred choice.Compared with carbody made of other steel,the stainless steel item that is widely used has many advantages,such as high strength and weight ratio,good corrosion resistance performance,long service life,beauty,high safety and less maintenance.This paper takes a stainless steel of SUS304 carbody with a peripheral skin spot welding and bonding structure as the research object,while the low thermal conductivity of the SUS304 causes the performance of the plate to be severely damaged under high temperature conditions and determines adopting resistance spot welding process with small thermal impact between the peripheral skin and stainless steel carbody,so the spot welding becomes the main bearing connection mode.If the stainless steel carbody employ only resistance spot welding connection process that has a relatively high requirement on the plate thickness,which may result in excess strength and does not satisfy the principle of lightweight design.Therefore,this paper adopts spot welding and adhesive bonding as for the thinner skin structure of the vehicle body,and performs an innovative work to research the strength of spot welding and bonded connection structure.Firstly,article describes the finite element simulation method of spot welding in detail,and combines the results of previous research on various spot welding joint models,and comprehensively evaluates various spot welding models from the aspects of simulation accuracy,modeling efficiency,and calculation cost;The commonly used finite element simulation method for adhesively bonged single lap joint is systematically described,mainly including solid element model,shell element model and spring element model.Then,single lap joint were established based on various finite element models,and comprehensive evaluations were made from comparation between the stiffness results of various finite element models and results from the Owen’s experiment of literature [61] as for modeling efficiency and simulation accuracy.Ultimately,using guidelines and recommendations for the respective models are gived.According to the research conclusions of the finite element simulation method of the spot welding and adhesively bonded joint,the finite element model of the stainless steel carbody with the spot welding and adhesively bonded structure is established by the finite element analysis software ANSYS.The spot welding joint adopt single beam model and adhesively bonded joint employ solid element model.According to professional standard ZB S 04001-89 to determine the load and load conditions of the carbody,simultaneously calculating the stress distribution of the carbody under each load conditions and estimating static strength of carbody base on EN 12663-1 standard.When the strength of carbody meet the standard requirements,assessing static strength of spot welding structure based on EN 15085-3 standard and evaluating static strength of the bonding structure based on the DVS 1618-2002 standard.According to the result of static strength analysis of the bonding structure,the bonding structure is optimized based on the design principle of the adhesively bonded joint and three optimized schemes of the bonding structure are constructed.Then,assessing the various bonding structural scheme by the previous assessment way.Finally,a more ideal bonding scheme is preferred.The dissertation systematically studies the connection mode of rail vehicle stainless steel carbody.The research results can provide theoretical basis for the lightweight design and manufacturing process of stainless steel carbody. |
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