The Lightweight, Finite Element-based Bus Body

Bus light-weight is one of the development trends of automobile in the 21st century. The technology of bus light-weight can reduce bus energy consumption, the bus-gas emissions and air pollution, and improve bus performance. Bus body skeleton is a kind of important loading component. Its mass occupies approximately one third of bus mass. The light-weight of bus-body-skeleton has a very important significance for reduction of bus mass. The research work on this paper is done surrounding a cooperation project between Yangzhou University and Yangzhou yaxing-Benz Ltd. This paper mainly study on bus-body lightweight of its 11-metre long city bus.On the basis of summarizing background of bus lightweight and domestic situation and international situation, the key technologies of bus-body finite element modeling are researched and summarized on this paper, bus force analysis are applied, grid modeling is built up, bus-body finite element modeling are simplified, load and boundary conditions are disposal using finite element software of MSC.NASTRAN combine with YBL6115 type bus example. The geometric models of bus are mainly created using surface model, and force analysis for YBL6115 type bus body are set given ten cases. On above basis, grid modeling is built mainly using quadrilateral grid. According to the characteristic of research object, the disposal of complex components,passengers,connecting department,bus coving,load and boundary conditions are researched, finally, bus body finite element modeling is established using shell element.In order to ensure the credibility of the results of simulation analysis, rationality and credibility for result of analysis and bus body finite element modeling are validated. On above basis, body bending case,body torsion case,the largest engine power case for linear static simulation analysis are mainly analyzed, and bus body lightweight clues are gained from result of analysis.Structure topology optimizing program for bus chassis,standing columniation of middle door and level bar is proposed by clues gained from finite element modeling analysis result. Through lightweight programme conformed by finite element modeling simulation, chassis still had reduction space; further lightweight programme was proposed to optimize adjustment. Improved design bus body weight was reduced X kg, compared to original design bus body.