【作者】 申伟；

【导师】 余强；

【作者基本信息】 长安大学 ， 车辆工程， 2011， 硕士

【摘要】 车身是客车结构的主要承载部件,要承受静载荷和各种动载荷的作用,因而对车架的强度,以及动态特性的要求都非常高。车架的动态特性设计不好,对客车的乘坐舒适性、操纵稳定性、安全性以及各零部件的可靠性都有不良影响。而车架的强度特别是动强度若不满足要求,会使车架结构受到破坏。因此对车身车架进行动态响应分析不仅可以评价车身车架自身的性能,而且还可以作为整车行驶平顺性等性能的评价指标,其结果还可以为车身车架的结构设计提供理论依据。本文利用有限元计算与分析的方法在三维软件CATIA建立三维几何模型的基础上对某客车厂的某车型客车车身车架进行了模态分析,通过动力学虚拟样机仿真分析软件ADAMS对整车进行了动力学仿真,通过有限元软件Hypermesh对车身车架进行瞬态响应分析。其中本文主要研究以下内容：第一：对该车身进行了模态分析,给出了该车身结构的前十阶模态分析。模态分析结果表明,车身结构的低阶模态频率处于路面激励频带之内,不利于车架的减振；车身前、顶部刚度较薄弱,易产生疲劳损伤；第二：利用ADAMS软件建立整车的刚柔耦合模型,并通过对整车在B级路面上进行的运动学仿真,找出车身柔性体应力较大的部位,并得出车身与车架相连的地方的所有力和力矩,作为进一步瞬态响应分析的载荷。第三：利用有限元软件Hypermesh对车身车架进行瞬态响应分析,计算车身在随时间的地面激励载荷下的位移和应力响应,找出车身和车架结构中较薄弱部位,为改进其结构及轻量化提供依据。通过对计算结果的详细分析,找出车身在动态载荷响应下位移、应力和损伤较大的部位,为改进结构设计提供理论依据提供了一种新的研究方法。更多还原

【Abstract】 Body and frame are main loaded parts of non-integrated structure of a bus,will bear the static and dynmic loads. So it is rather important for both its strength and dynamic characteristic design. The dynmic charaeteristic of the frame will aeffet the ride comofort, the contorl stability and the seucrity of thebus,and the relibaility of the components. And if the strength,espeeially the dynamic strength can’t meet its requests, the frame may be destoryed. Therefore, dynamic response analysis of the body and frame can be evaluated not only on their own performances,but also on their travel stability and other performances, its result can also provide a theoretical basis for body and frame’s structure.Taking the model analysis for the body and frame of bus model which based on CATIA make up by using he finite element method of calculation and analysis;Taking dynamics simulation in ADAMS;Taking transient response analysis of the body and frame by Hyperworks. In this thesis, the following works were mainly studied.First:The modal properties of the frame were analyzed through the FE method, and the first thirty natural frequencies and ten vibration modes were given. The modal analysis showed that the lower modal frequency of this frame was within the scope of the road excitation frequency, and this fact was not propitious for the vibration decreasing. The foreside of this frame was weak in stiffness and vulnerable to fatigue damages.Second:Taking dynamics simulation in ADAMS,found out those nodes which has the larger stress on flexible body,and received the variation curve along the time of those nodes belong to the frame and suspension’s force and the moment at the same time, thus became the random load in transient response analysis.Third:Taking transient response analysis of the body and frame by Hypermesh, and found out the larger displacement and stress parts of the body and frame. To improve its structure and quantification offers a basis.Through a detail analysis of the results, we obtained the places of the bodyand frame of the lager displacement, stress and fatigue damage under thedynamic load,which can be privided a new way for a theoretical basis and the structural design.更多还原