Analysis On Typical Conditions Of Coach Frame And Application Research Of Floor Skeleton On Lightweight

With the global environment worsening and energy crisis growing, safety, energy saving and emission reduction have become the major issues faced by the automotive manufacturing industry. Some research results show that the fuel consumption of a car would be reduced by6%-8%when its weight reduced by10%. Usually, the body weight is about30%of a car’s total mass, while its fuel consumption accounts for70%of the total. So the lightweight body technology plays a pivotal role in the whole car’s lightweight process.There are two main ways to achieve automotive lightweight body. The first way is using the new lightweight materials with higher strength and lower density, such as aluminum alloy, magnesium alloy, high-strength steel, composite material, etc. The second way is making the body parts thinner, hollow, miniaturized, composite and designing more reasonable body structure and improving the manufacturing process of the auto body parts. The first approach is the mainstream of the automotive lightweight technology.Many lightweight materials have been used in the auto body manufacturing industry. The second approach is reducing the body frame weight through the analysis and optimization of the body structure with the use of the computer finite element analysis techniques and optimization design method. When the two methods complement each and combine effectively, the auto body weight can be maximumly cut down on the premise of maintaining the body strength.As one of the new materials, aluminum has become the most widely used engineering material which was used in automobile. Aluminum has the advantages of light specific weight, high strength ratio, good ductility, excellent resistance to corrosion, high elasticity,easy recycling,ow cost etc. Meanwhile, throw mixing with different proportions of other elements and using different processing technologies, aluminum can be converted to aluminum alloy material with superior performance, such as cast aluminum alloy, wrought aluminum alloy, superplastic aluminum alloys, fiber-reinforced aluminum alloy aluminum matrix composite, etc. Thus, to meet different requirements of the material characteristics for different automobile components. Therefore, aluminum alloy material is widely used in automobile engines, cooling equipment, wheel rims, bumpers, chassis parts, as well as exterior body panels.This paper is based on the theory of the stiffness of the thin-walled beam.The work includes researching on the relationships of each parameters which effect the stiffness of thin walled structure with closed rectangular cross-section and analyzing the optimal values of sectional parameters among different materials under the same stiffness.The application of aluminum alloy materials on the automobile body, especially on the bus body frame is also researched based on the analysis of relative mechanical properties and structural properties of the aluminum alloy materials.Through the analysis of bus body frame mode, stiffness and strength under typical working conditions, the replacement parts with aluminum alloy material are determined. Finite element simulation is carried out at the same time.Then though comparing the stiffness and strength of the same part and analysising the results, the conclusion can be obtained. Under the premise of maintaining the strength and security, the total body weight is reduced and the bus body frame structure with lightweight and high strength achieves the set goal.