Lightweight Research Of A12-meter Bus Body Structure

With the rapid depletion of natural resources, resource-exhausted cities become more; Withthe increase in emissions of air pollutants, air pollution spreads throughout China. According tothe survey, vehicle exhaust has become the main pollution in large cities. In order to saveresources and reduce emissions, the Chinese government is trying car purchase restriction inmore than one city, and call on citizens to go out by public transport. As the protagonist of theurban and rural public transport, buses are playing an important role in energy conservation andemission reduction. The data show that the lightweight of body structure has a significant effecton energy saving, so this paper does some research on a12-meter highway bus lightweight,which can play a greater role in energy conservation, and provide reference data for similarmodels lightweight work.With domestic and overseas industrial technology progressing, lightweight methods of busbody structure are developing. Through the relevant research, I found that lightweight method ofbus body structure is divided into three areas:1) the rational use of new materials, mainlystrength/density ratio high materials;2) the introduction of new manufacturing processes;3)body structure rational design. Due to manufacturing cost, new materials and new manufacturingprocesses apply on buses less, which will develop fast in the future as a lightweight method. Butwhether past, present or future, the body structure reasonable design is always fundamentallightweight method. This article does some research on K6121bus body structure lightweight byrational design, and achieves its lightweight goal.The development of CAE technology makes it possible for people to carry lightweightdesign out by arranging structure rationally. Generally, the method to achieve lightweight byarranging structure rationally is divided into two sides. One is structure beams rational layout,and the other is sectional dimension optimization.This article arranges bars of body structure rationally based on the principle of non-axialstress minimized. For the efficiency, the article references many similar models. Based onprinciple of non-axial stress minimized, using stress-internal force analysis, K6121modelarranges beams of body structure mainly at the rear chassis bracket, the engine support structure,middle door steps, the top frame of middle door, left and right side wall. These structureimprovements not only make K6121body weight loss, but also improve stiffness and strength oflocal structures, which provides a larger space for further lightweight of body structure. K6121model loses a total weight of76.91Kg by arranging structure beams rationally, accounting for7.49%of the body structure weight, which shows non-axial stress minimized method plays animportant role in structure beams rational layout.After body structure is done, the article does further lightweight design to K6121low-stressbeams, by sectional dimension optimization method. Sectional dimension optimization method isa simple, direct and effective lightweight method. K6121body structure made lightweight designsuccessfully with large cross-section beams, luggage compartment floor structure, the front doorsteps structure, the structure placed battery and so on, achieving the target of further lightweight.K6121model loses a total weight of268.57Kg by sectional dimension optimization method, accounting for7.49%of the body structure weight, which shows sectional dimensionoptimization is a very effective lightweight design method.After lightweight design of K6121body structure, the paper carries out the basicperformance analysis of new body structure. Results show that: new body structure almost notexist high stress rods, beams distributing more rational. Calm stiffness and dynamic stiffnessmaintained the same level as the original body structure, and strength and shedding deformationimproved greatly. In summary, with maintaining performances of strength, stiffness and sheddingdeformation, K6121model loses345.48Kg, accounting9.64%of body structure weight.