导　　师： 陈吉清

学科专业： 080204

授予学位： 硕士

作　　者： ;

机构地区： 华南理工大学

摘　　要： 由于客车制造技术越来越先进,未来客车制造技术的主要发展趋势就是生产安全、可靠、轻量化的整车结构。目前,国内外对客车车身骨架结构在动态载荷作用下的结构疲劳强度分析方法研究的还比较少,主要原因是由于客车车身骨架结构现场耐久性实验费用昂贵,而且周期长。而如果利用传统的准静态分析方法,通过施加常幅载荷谱将静强度分析结果直接应用在车体结构的疲劳强度评估上,虽然方法简单,但会与实际服役的客车车身骨架结构疲劳强度产生较大的偏差。本文基于相关领域结构疲劳研究成果,提出了一种利用多体动力学和有限元分析相结合的方法来对客车车身骨架结构进行疲劳寿命评估,并与静态有限元分析结果进行对比。 本文的主要内容是预测车身骨架结构的疲劳寿命。文章首先建立客车车身有限元模型,通过实验验证车身有限元模型,接下来建立了整车多体动力学模型和路面激励,使整车匀速地在建立的随机路面上仿真,获得车身疲劳寿命分析的动态载荷时间历程。然后分别对车身骨架进行了弯曲和扭转工况下静态分析,初步评估车身结构静强度危险位置。接着又对车身骨架在随机激励下进行了瞬态动态响应分析。最后结合车身骨架结构材料S-N曲线和多体动力学仿真获取的动态载荷时间历程对车身骨架进行疲劳强度分析,并比较静强度分析和疲劳强度分析的位置,发现两种结果有一定的出入。 总之,文章比较系统的阐述了基于多体动力学和有限元分析研究客车车身骨架结构疲劳特性的基本思路。利用这种集成计算方法可以在产品的开发早期较为准确的预测结构的疲劳特性,为实际研究负载结构的疲劳寿命预测和有效进行结构耐久性测试提供了良好的理论依据。 As the bus manufacturing technology is advanced more and more rapidly. The main development trend of future bus manufacturing technology is producing safer, more reliable and lightweight vehicle structure. Nowdays from all over the world the research methods on bus body frame structure under dynamic loading are still relatively small, mainly due to the durability of bus body frame structure field experiment is expensive, and it will take a long time. If using traditional methods quasi-static analysis, by applying constant amplitude loading spectrum the result of static strength analysis will be directly applied to evaluate the fatigue strength of body structure, though it is simple, but it will produce large deviation from the actual service of the bus body frame structure. Based on structural fatigue research in related fields, the article brings forward a method assessing the fatigue life of the bus body frame structure by combing a multi-body dynamic and finite element analysis and compares with the result of static finite element analysis. The main content of this article is to predict the fatigue life of the body. First the bus body finite element model is established, and then verified by experiment. Second establishing a multi-body vehicle dynamics model and the driving road, so that uniform vehicle is put on the stochastic road and incited to access to body fatigue life analysis dynamic load time history. Then the article conducts static analysis of the body frame under bending and torsion condition, so that preliminary to assess the risk static strength location of the body structure. Followed by random excitation of the body frame under transient dynamic response analysis. Finally combing material S-N curve of body frame structure and dynamic load time history derived from multi-body dynamics simulation to conduct the fatigue analysis of the body frame, and compare the weak location of the static strength analysis and fatigue analysis and find two results have greater access. In short the article gives a systemic basic researching idea of fatigue characteristics of the bus body structure based on multi-body dynamics and finite element. Using this integrated method could be more actual to predict early fatigue characteristics of the structure at the early time of the product development, it will provide a good theoretical basis for the fatigue life prediction and effective structural durability testing of the loading structure.

关 键 词： 客车车身骨架 多体动力学 有限元 疲劳

分 类 号： [U463.82]

领　　域： [机械工程] [交通运输工程] [交通运输工程]