新能源汽车后面碰撞试验技术研究

基于新能源汽车的结构特点以及与传统汽车在结构布置上的差异,对国内新能源汽车后面碰撞试验相应的法规和标准进行了分析,并对新能源汽车后面碰撞试验程序做了说明,通过对某新能源汽车的实车后面碰撞试验及与原型车的后面碰撞试验结果比较分析,揭示了新能源汽车在后面碰撞试验中的特点以及可能存在的问题。     

Development of lumped-parameter mathematical models for a vehicle localized impact

In this paper, we propose a method of modeling for vehicle crash systems based on viscous and elastic properties of the materials. This paper covers an influence of different arrangement of spring and damper on the models’ response. Differences in simulating vehicle-torigid barrier collision and vehicle-to-pole collision are explained. Comparison of the models obtained from wideband (unfiltered) acceleration and filtered acceleration is done. At the end we propose a model which is suitable for localized collisions simulation.     

均分区域法标记试验区域的行人保护试验研究

现阶段我国仍属于人、车混合的交通状况,车辆碰撞事故频繁发生.在车辆与行人碰撞事故中,行人属于弱势群体,加上现阶段车辆缺乏对行人保护的措施,行人伤亡严重.在汽车行人碰撞事故中,行人头部受重伤是造成行人死亡的主要因素;行人腿部受伤是造成行人受重伤的主要因素.基于两款车辆以均分区域法标记试验区域的行人保护头型碰撞测试数据,对...     

关于油气弹簧气体初始压力优化设定的分析

油气弹簧集弹性元件和阻尼元件于一体,以惰性气体为弹性介质,因单位质量储能比大,从而使车辆固有振动频率低,减振和缓冲性能好,并且具有优越的非线性弹性特性,能够满足工程越野车辆的平顺性要求。相比于其他类型的悬架系统,油气弹簧采用的油气悬架系统具有非线性可变刚度、结构紧凑和可调节车姿等显著特点,是一种性能比较理想的悬架系统。本文对某型越野车悬架系统中油气弹簧气体初始压力进行了计算和分析,并将计算结果应用到试验中,然后通过对气体初始压力的调整,使油气弹簧得到较低的固有频率,以易于实现对车身高度的调节,这些优点使其在越野汽车上有较好的应用前景。     

面向众泰2008汽车的螺纹剪切式吸能装置的设计制造

为了探讨螺纹剪切式吸能装置的实车匹配性,进而验证其在实车碰撞过程中的吸能可行性,针对众泰2008这款车型的结构特点,修正已有螺纹剪切式吸能装置结构参数,设计制造出与之匹配的螺纹剪切式吸能装置,并实现其在实车上的安装与应用.这样既验证了螺纹剪切式吸能装置的实车匹配性,也为进一步的实车碰撞试验奠定基础.     

通过多体仿真计算轿车姿态的方法

轿车在不同载荷下的姿态是由前悬架高度以及后悬架高度共同确定,它对外观造型、底盘通过性、操纵稳定性以及舒适性等会产生影响,轿车姿态本质上由悬架弹簧的长度控制。通过建立一套利用多体模型仿真计算方法,来确定悬架弹簧长度,以调整车辆的静止姿态,使其满足设计要求。     

多元胞结构在机车吸能装置中的应用

在车辆被动安全防护中,吸能部件的设计研究是其基本的一个环节.设计耐碰撞机车吸能装置可在车辆发生碰撞后迅速更换损坏部件,减少维修周期,节约维修成本.薄壁金属吸能结构作为一种高强重比、低成本、高吸能效率的结构,广泛应用于飞机、汽车、铁路列车和轮船等几乎所有交通工具的碰撞动能耗散系统中.对四元胞正方形结构和几种常规截面形状单...     

A Contact Force Model Considering Meshing and Collision States for Dynamic Analysisin Helical Gear System

The current research on gear system dynamics mainly utilizes linear spring damping model to calculate the contact force between gears. However, this linear model cannot correctly describe the energy transfer process of collision that often occurs in gear system. Focus on the contact-impact events, this paper proposes an improved gear contact force model for dynamic analysis in helical gear transmission system. In this model, a new factor associated with hysteresis damping is developed for contact-impact state, whereas the traditional linear damping factor is utilized for normal meshing state. For determining the selection strategy of these two damping factors, the fundamental contact mechanics of contact-impact event a ected by supporting forces are analyzed. During this analysis, an e ect factor is proposed for evaluating the influence of supporting forces on collision. Meanwhile, a new restitution of coe cient is deduced for calculating hysteresis damping factor, which suitable for both separation and non-separation states at the end of collision. In addition, the time-varying meshing sti ness(TVMS) is obtained based on the potential energy approach and the slice theory. Finally, a dynamic analysis of a helical gear system is carried out to better understand the contact force model proposed in this paper. The analysis results show that the contribution of supporting forces to the dynamic response of contact-impact event within gear pair is important. The supporting forces and dissipative energy are the main reasons for gear system to enter a steady contact state from repeated contact-impact state. This research proposes an improved contact force model which distinguishes meshing and collision states in gear system.     

Collision between a ring and a beam

With car–parapet collision accidents in mind, a normal collision between a free-flying half ring and a simply supported beam with/without axial constraints is studied, in which an elastic–plastic half ring with an attached mass and the elastic–plastic beam are taken as the simplest models of a car and a parapet, respectively. Particular attention is paid to the energy partitioning between the two structures and the evolution of the contact regions during collision. A mass–spring finite difference (MS–FD) model is employed whilst the large deflection and axial stretching/compression are incorporated. The numerical results show that the less stiff (i.e. softer) structure will dissipate more energy and the contact regions will move away from the initial contact points. With the increase of the relative thickness of the beam to the ring, the final deformation of the half ring will transform from a “U” shape to a “W” shape.     

基于流固耦合的液压缸碰撞研究

针对经典碰撞模型的局限性,通过采用缸筒弹簧模型,建立了新型液压缸碰撞模型;通过构建描述液压缸碰撞的流固耦合方程组,利用有限元软件ADINA分析了有无流体及不同负载力对液压缸碰撞位移、速度和应力的影响,分析结果表明流体对于液压缸碰撞具有明显的阻尼作用。     

基于碰撞安全的复合材料尾门设计

由于环保和节能的需要,汽车轻量化已经成为世界汽车发展的潮流.介绍了复合材料的优缺点,并将复合材料应用到汽车尾门,通过材料选型、结构设计以及碰撞安全的CAE仿真分析,设计出后部碰撞性能与传统钣金尾门性能相当的复合材料尾门,最终轻量化比例达到35.3％.     

湿式离合器流场与作用力模型试验研究

轴向和周向作用力影响湿式离合器宽速域范围工作性能。针对湿式离合器对偶片间带排转矩与轴向力演变问题,根据湿式离合器简化结构,开发湿式离合器模型流场可视化与受力测试试验装置。通过试验测试分析流场演变过程,得到对偶片间带排转矩与轴向力参数影响规律。结果表明,流场包括全液相流和气液分层流两种基本流型,在纯液相和纯气相区之间可形成一个稳定的边界。随着转速的增大、流量的减小和间隙的增加,对偶片间流场中的油液体积分数减小,两相边界向内侧移动。流量和间隙对带排转矩的拐点有显著影响,减小流量和增大间隙都可降低拐点对应的转速。随着转速增大、流量减小和间隙增加,对偶片间轴向力呈现下降趋势。在带排转矩拐点附近,轴向力的作用方向发生改变,且最终轴向力几乎减小到零。     

立体车库过放液压缓冲系统研究

提出并设计了立体车库过放液压缓冲系统,选型计算了系统关键元件参数,基于AMESim搭建了过放液压缓冲系统仿真模型,得到了载车板速度位移和缓冲缸压缩腔压力流量动态性能曲线,分别研究了不同溢流阀弹簧预压缩量和刚度对缓冲缸压缩腔及载车板位移的影响。仿真结果表明：该系统能有效吸收载车板过放能量;在不发生撞缸的条件下,减小溢流阀弹簧刚度和预压缩量有助于降低缓冲缸压缩腔压力冲击和提高缓冲缸吸能量。     

钢板弹簧横置对车辆操纵稳定性影响的研究

针对某车型前悬架,分别采用螺旋弹簧、钢板弹簧进行布置,以此研究钢板弹簧横置对车辆操纵稳定性的影响。在ADAMS软件中搭建车辆前悬架仿真模型,通过仿真对比,得出在悬架刚度相同的情况下,采用钢板弹簧横置方案,前悬架侧倾角刚度相比采用螺旋弹簧布置方案增大42.86%。通过.整车稳态回转工况仿真,得出采用钢板弹簧横置方案可以使车辆侧倾梯度减小17.4%,并使车辆不足转向度减小8.33%。     

Investigation of vehicle crash modeling techniques: theory and application

Creating a mathematical model of a vehicle crash is a task which involves considerations and analysis of different areas which need to be addressed because of the mathematical complexity of a crash event representation. Therefore, to simplify the analysis and enhance the modeling process, in this work, a brief overview of different vehicle crash modeling methodologies is proposed. The acceleration of a colliding vehicle is measured in its center of gravity—this crash pulse contains detailed information about vehicle behavior throughout a collision. A virtual model of a collision scenario is established in order to provide an additional data set further used to evaluate a suggested approach. Three different approaches are discussed here: lumped parameter modeling of viscoelastic systems, data-based approach taking advantage of neural networks and autoregressive models and wavelet-based method of signal reconstruction. The comparative analysis between each method’s outcomes is performed and reliability of the proposed methodologies and tools is evaluated.     

基于碰撞安全性具有引导结构汽车前纵梁设计

前纵梁抵抗弯曲变形的能力直接影响整车碰撞安全性.针对前纵梁进行引导结构优化设计,以提升抵抗弯曲变形能力.基于前纵梁弯曲变形工况,分析前纵梁弯曲变形的截面受力变形模式;外延变形具有最好的弯曲变形承载能力;设计具有外延变形和对称变形交替出现的前纵梁结构,选用开引导槽的结构形式进行优化设计;基于碰撞法规,选取正面100％刚性...     

真空断路器触头碰撞的分析和优化

真空断路器在合闸时,由于动静触头发生碰撞,它们之间会产生一定程度的弹跳,从而引起触头之间的高压拉弧.高压拉弧容易引起触头熔焊,影响开关工作的可靠性,甚至损坏开关.因此断路器的设计常常是在触头端设置弹簧,以缓冲动静触头之间的碰撞.运用虚拟样机技术,对静端加缓冲弹簧的真空断路器合闸过程进行了仿真,对缓冲弹簧的刚度进行了优化...     

轿车追尾碰撞仿真及结构耐撞性改进研究

以国产某轿车为研究对象,按照GB20072—2006对该车进行追尾碰撞模拟仿真分析和评价。通过对该车尾部后纵梁和后围板进行结构方面的改进研究,有效地提高了汽车尾部耐撞性能和燃油系统的安全性。研究结果为今后开展汽车追尾碰撞仿真及提高尾部耐撞性能提供了可借鉴的方法。     

一种基于AT89C51的汽车倒车防撞报警系统的设计

针对汽车倒车防撞问题,提出了将超声波测距系统和单片机结合,给出了一种基于AT89C51单片机的倒车防撞报警系统的设计,仿真实验结果验证了此设计的高效性。     

专用车膜式空气弹簧特性研究

对专用车空气悬置进行适应性改型,根据气体状态方程,得到膜式空气弹簧刚度与固有频率的表达式,研究了膜式空气弹簧初始气压、初始容积和有效面积对刚度特性的影响。结果表明,专用车膜式空气弹簧的刚度呈非线性,其固有频率在车桥载荷变化范围内保持基本稳定,适于载荷变化大的专用车悬置使用。