The Cracking Analysis And Research For Back Door Of Passenger Vehicle

The automobile is the indispensable transportation tool that the modern life,modern economical construct and modern national defence .As amulti-performance vehicle, passenger vehicle has wide range of application andhuge function. After China join WTO, the automobile industry meets certainimpact, the competition of the car industry is already very drastic currently .in carindustry's winter the profit of passenger vehicle is also decrease year by year.Because of the high product cost, no controlling the core technique of the designand manufacturing and depending on the foreign technicle support, The simplicialusing the foreign mature products in the earlier time do not fit for the developmentin the future and will not have international competition ability.In order to usingforeign technical to exceed the foreign company, the local automobile companieshave already been aware of building up it's own technique system and carried onthe independent technique development.This topic is about some company's vehicle happen to bring crack in theoutside of the back door after driving a period of time. This not only affects thebeauty of the bodywork, but also make customer doubt to the product quantity .Sobreaking the image that product is in the consumer's heart .As a style of vehicleintroduce from Toyota, the passenger vehicle basically followed to use theproduction of the Japanese Toyota manufacturing craft, did not carry on theimprovement to chinese actual circumstance. For the drastic market competitioncompany must improve the product quantity and the technique content. Therefore,the enterprise decides to thoroughly analysis, study this problem's reason.Afterknowing the regulation that problem appears actually, we can set up the fundationfor the independent development of the new product in the future. First, the topic analyse the back door's rationality of structure design, adoptingFEA method to analyze the structure's characteristic of stress, distortion andmold.As a method of currently extensive adopted by mechanics research andoptimal design, FEM is prove to be one of the most effectively and successfullymethods .But it is a more complicated work to carry on a analysis to the parts ofbody,mainly including to make sure the calculation principle, establishmathematics model, build up a model, make sure the typical model work conditionand load, boundary condition, FEA calculation and deal with the result , thenanalysis the results for improving. For the complicated structure of the body, and complicated curved facecharacteristic, to build up a back door's structure reasonable under various workcondition, relate to the credibility and calculating efficiencies of the result.Therefore, in this text the back door's model was simplified such as removing theunimportant holes and simplifing the unimportant curved face structure as the flatsurface. According to the work condition of the door, choose a few typical workcondition and limit work condition to carry on the calculation. Choose shellelement to simulate the sheet metal's characteristic. From the results of the static state and the dynamic state analysis, it reflectsthe stress concentration the corner of door plate,and these lead to the problem onthe back door.So we make sure the design of the product is unreasonable. The second, carry on the analysis from the manufacturing craft of theproduct.During the process of punch ,the mould's aging may cause stressconcentration in outside panle's corner.so need repaire the mould, enlarge radiusvalue, make slow transition of surface, and notice the mould clean. During the weld...