【作者】 梁霖锋；

【导师】 陈铭年；

【作者基本信息】 福建农林大学 ， 机械设计及理论， 2009， 硕士

【摘要】 在社会主义新农村建设中,发展农村交通事业已成为一个重要课题。而乡村公路营运客车在发展农村交通事业中起着十分重要的作用。由于农村道路条件较复杂,特别在山区,乡村公路营运客车易发生翻车事故,经常导致车身局部断裂或车顶塌陷,给乘客带来严重的伤害。农民出行经常要携带体积较大、重量较重的农副产品,如果人货混装,在发生事故时,这些农副产品可能将对乘客带来伤害。为保证乘客安全,乡村公路营运客车的车身结构设计变得尤为重要。因此,对乡村公路营运客车车身结构进行研究意义重大。6米乡村公路营运客车,是农村客运的主力车型。本文比较归纳了现有6米乡村公路营运客车的结构特点,并结合我省省情,提出了关于我省发展农村客车的几点思考。在单舱、两舱结构的选择上,地处平原的农村公路,可将单舱式乡村公路营运客车作为选型和进一步改进的参考。地处山区的农村公路,可将两舱式乡村公路营运客车作为选型和进一步改进的参考;在山区行驶的农村客车顶盖和窗立柱承载能力应足够;对于两舱式乡村公路营运客车,宜将隔仓设置在乘客区外部,并与乘客区密封隔离,可以通过对后围进行修改,以达到真正的人货分离;在车窗和靠窗座椅之间的合适位置,设置横栏,对于提高乘坐安全性,消除隐患是必要的。本文选择一款本省设计和制造的6米两舱式乡村公路营运客车FJ6606为例,对该车进行顶盖承载能力分析、车身结构强度分析以及动态分析,对该车的结构性能进行评价,并提出了结构改进的方法和措施。计算分析采用的是有限元法和ANSYS软件,分别建立了梁单元模型和壳单元模型,并比较分析结构强度和动态分析时两种模型的计算结果。计算表明:采用梁单元模拟该车骨架时,该车在弯曲工况的应力裕度分别为5.07,左弯扭组合工况的应力裕度为2.13,右弯扭组合工况裕度为2.07。行李舱的强度均满足要求。该车的结构强度是足够的。采用壳单元模拟该车骨架时,该车在弯曲工况的应力裕度分别为2.85,满足强度要求。左弯扭组合工况最大应力SMX=329.12MPa,右弯扭组合工况最大应力SMX=380.98MPa,均超过材料的屈服极限。而行李舱的强度满足要求。利用梁单元模型对该车计算顶盖承载能力,表明顶盖承载能力不足,顶盖部分横梁需要加强。本文通过改变杆件截面形状和增加杆件厚度等方法,对顶盖结构进行改进,提高了该车的顶盖承载能力。模态分析表明,该车的车身低阶频率避开路面激励频率和发动机激振频率,该车的动态性能良好。比较梁单元模型与壳单元模型的计算结果,弯曲以及弯扭组合工况时,两种模型计算得出的整体应力分布趋势大致一致,而壳单元模型的最大应力值明显高于梁单元模型的最大应力。并提出在客车结构设计中,梁单元宜用于方案设计阶段,而壳单元宜用于细节结构设计阶段。而运用加角板以及焊贴薄钢片等方法,可有效的降低高应力,提高结构强度。模态分析时,壳单元模型计算得出的该车骨架的固有频率较梁单元模型小,两种模型得出的振型大部分一致,部分振型不同。本文是用有限元法对乡村公路营运客车车身结构分析的一个工程实例,对其他乡村公路营运客车的设计具有一定的参考意义。更多还原

【Abstract】 Development of transportation in rural aeras has become a hot spot , which will push forward tthe construction of the socialist new countryside. Rural bus plays an important role in this process. The rural bus is apt to have accidents in the rural highway , which will cause the fracture of the bus structure and hurt the passengers. The peasants often go out with large and heavy agricaltural products. They will also hurt the passengers when the rural bus having accidents. So the design of rural bus structure is important for the safety of passengers.6-meter rural bus is main vehicle in rural areas. This paper compares structural featuers of some exisiting rural bus and gives some suggestions on developing rural bus in Fujian Province. The singe compartment structure of rural bus is a good choice in plain area . The double compartment structure of rural bus is a good choice in mountain area .It is necessary to select shape steel tube for the design of the bus roof and window pillar. It is proper to set the compartment structure out of the passenger zone . The sturcture altertion in rear quarter panel is feasible to fufill the division of passengers and agriculture products. It is also necessary to set a cross bar between the windows and seats to ensure the safety of passengers.FJ6606 is a rural bus , which is designed and manufactured by a bus company in Fujian Province. Taking FJ6606 bus for example, the finite element method is used to analyse roof supporting capacity , structural strength and dynamic performance of this bus.With the calculation of Ansys , it indicates that FJ6606 has a good performance in the structural strength and dymaic performace. But the roof supporting capacity is not enough, some of the cross beams need to improve. The methods are used to improve the structure of roof .更多还原