Study On The Analysis Of Coach Body Structure's Lightweight

Automobile industry is in the rapid development, its high energy consumption,high pollution has caused increasingly serious social problems. Reducing vehicle mass is not only to improve vehicle handling and stability, ride comfort, but more important is to address energy conservation, environmental protection and other social problems.In this paper, on the foundation of lightweight research on domestic and foreign cars, through simple analysis in the use of lightweight materials in the design of the bus, based on structural strength variation in lightweight design and crashworthiness etc, pointed out that modern design method is a shortcut to solve this problem.Specific research process of this paper is:first, detailed analysis of the thin-walled beam section properties of basic components, and then use ANSYS software for static analysis of a 6127 bus to understand the situation of vehicle stiffness and strength, then, the optimization method was used to analysis the original steel structure and lightweight aluminum alloy structure after being substituted.Through the analysis of Thin-walled beam cross-section characteristics, we knew that: section thickness minimal impact on SME value, less thick is obvious of weight loss effect, but the crash test results show that thickness can not be arbitrarily reduced; Width and height, of cross-section have a greater impact on the SME, increasing the width, height of cross section, its component's bending, torsional stiffness will be improved, which significantly increase when the height being large, and crash test shows the perimeter of the rectangle could be better in energy absorption,and different value of width to height have greater impact on the energy absorptionStatic analysis results of a 6127 bus show that with the exception of the local stress concentration of the partial strengthening, the body stiffness and strength can basically meet the requirements of using in project. Through structure optimization in floor structure, we can see, only to change the cross section of the perimeter or the thickness, there will be a greater strength or lack of rigidity problems, optimizing the circumference and thickness together will be better.when the steel floor structure utilize comprehensive optimization program, the mass reduce from the 236.356Kg to 208.015Kg, reduce 11.99% on the basis of the original one. After the substitution of aluminum alloy, the mass decreased to 162.158 Kg, can be reduced by 31.1% based on the original steel structure, In addition that the two optimization results slightly increased stress level, the structural stiffness is the same as the original one, meeting the requirements of project, which indicate that lightweight synthetic optimization methods to solve this problem is very effective.