Optimization Design And Analysis Of A Vehicle’s Subframe

Automobile industry, as a pillar industry of national economy has obtained rapid developmentin recent10years, and it has accounted for more than8%of national GDP according to a2009car yearbook statistical data. The automotive research and development has always been a weaklink in the development of Chinese auto industry. According to a recent years of China’s autoindustry policy, our country has attacheed great importance to the development of the automobilechassis, Which fully shows that the chassis parts is very important and hard to research or develop.And in the development of chassis components, durability design is especially Paramount.Subframe as the largest chassis parts is also one of the most vital components of automobilechassis,and the main core design emphasize particularly on the stiffness, strength, durable,lightweight, harshness (NVH), collision, etc. This paper take subframe of a vehicle as an example,after extracting the working condition load, the strength、durability、frequency and stiffness areanalysed on the basis of half dynamics. Meanwhile, compare and test the result to ensure anoptimal design solution after the performance indicators were met. This paper has carried outmainly the following aspects of work:Firstly, chassis suspension system is selected and the dynamic model of half a car’ssuspension system is built.After a variety of vehicle working conditions is determined and vehicledynamics is analysed according to certain failure mode and data experience, the frame partsdesign parameters and the working condition of durability is received.Secondly, the simulation load spectrum and data processing is discussed. Deal with loadspectrum by the use of Rain flow counting method,and investigate the difference betweendynamic load spectrum and and static loading conditiong in the use of subframe design andanalysis by the principle of equivalent damage.Thirdly,strength failure mode with high-precision were obtained and the feasibility andstability of the optimum plan was analyzed after Static Strength analysis、durability life analysisand assembly level of nonlinear analysis were carried out,which was established on the workingcondition and the test condition.Fourthly,refining the design.Combining lightweight designt、opological optimization、costcontrol、research efficiency and manufacturing feasibility, the best design was obtained by theues of orthogonal test method.weighted flexibility method is discussed in the sheet metal propertiesof the application of auxiliary subframe optimization design. Finally, optimal variant design and analysis to the auxiliary subframe is proceeded based onthe optimized design of strength, fatigue, frequency and stiffness, combined with vehicle harshness(NVH) and collision、the weight factors and cost control, that the customers are satisfied.Theresearch results of this paper can be used as the basis of obverse design for automobile chassis parts.