基于RCAR试验的汽车低速碰撞性能设计

介绍了RCAR低速碰撞试验与评价方法,RCAR碰撞结果对车辆保险费用的影响以及车辆低速碰撞性能设计的思路和方法,并以长城某轿车为例,利用仿真方法,从碰撞能量计算、吸能弹簧单元和吸能盒结构设计等方面具体阐述了车辆低速碰撞性能设计过程.     

碰撞试验:为安全而生——走进沃尔沃商用车碰撞试验室

正本文通过对沃尔沃卡车碰撞试验室一次碰撞试验全面而详细的介绍,向读者展示了碰撞试验的整个过程,以此来表明沃尔沃对于车辆安全性的格外重视。众所周知,沃尔沃汽车一向以"安全"而著称,无论是乘用车还是商用车,车辆的安全性都是沃尔沃工程师在开发设计时所考虑的重要因素。因此,沃尔沃投入了大量的人力和物     

基矛ADAMS散落物运动仿真研究

利用机械系统动力学分析软件ADAMS对散落物进行参数化建模，并进行了试验仿真，初步实现了在算机上对汽车散落物的仿真分析，通过与经典抛物运动模型的比较，验证了基于ADAMS散落物运动模型的可行性。     

基于高速摄像的汽车碰撞动态数据分析技术

汽车碰撞试验是评估车辆安全性的核心环节,而高速摄像技术在这一过程中发挥着不可或缺的作用,通过捕捉车辆在碰撞瞬间的高速动态,测试车辆在碰撞条件下的物理反应。本文提出了一种基于高速摄像的汽车碰撞动态数据分析技术,通过数据捕捉、关键帧与时刻标记的方式记录并分析碰撞动态过程,为车辆安全性能评估提供支持。     

车辆与行人碰撞试验工况中行人保护研究

车辆碰撞行人在城市道路交通事故中较为常见。为完善行人保护相关标准法规,进一步降低交通事故中的行人伤亡率,本文基于160起车辆与行人碰撞事故的形态特征及行人损伤机理的分析,搭建了车辆与行人的碰撞工况场景,并通过某轿车的碰撞试验真实复现了道路交通中车辆与行人的碰撞过程,探究了行人的动力学响应和损伤特性,为进一步完善行人保护相关标准提供重要的参考价值。     

交通事故处理中动态追尾和静态追尾的甄别

动态追尾与静态追尾的甄别是认定追尾交通事故责任的一个关键环节。本文从现场范围、现场散落物的分布特点、现场痕迹的形态特点及肇事车辆的结合形态这四个方面来进行动态追尾与静态追尾的甄别。     

碰撞后快速脱离的新型指示牌立柱设计探讨

汽车与公路指示牌立柱的碰撞是极其危险的交通事故。本文分析了汽车与公路指示牌立柱碰撞事故中车辆受损的原因,提出了碰撞后快速脱离的新型指示牌立柱,并利用有限元方法对汽车碰撞指示牌立柱进行仿真模拟试验,根据研究结果证明结构合理正确,能够在碰撞中减少车辆和乘员的的损伤程度。     

汽车行人碰撞抛射仿真模型

利用PC-Crash软件进行车辆与行人的碰撞仿真试验,提出了第一落地点抛距理论模型,将车辆与行人的碰撞划分为车辆前部与行人的后部和侧面碰撞两种类型,碰撞车型选择当前广泛使用的发动机舱盖略向前下倾斜的梯形前端轿车,建立了车辆与行人后部、侧面碰撞抛距模型和综合碰撞抛距模型,分析了行人相对车辆前端的不同位置对抛距的影响。最后将文中提出的模型与国外行人抛距模型进行对比,结果证明该模型是有效的。     

碰撞试验程序与车辆相容性的关系

阐述了正面、侧面碰撞试验中常用的试验壁障对不同尺寸车辆相容性的影响。汽车在碰撞中前部所产生的破坏力的最大值是衡量车辆相容性的一个重要指标,根据力学原理,使用固定壁障会导致大型车辆前刚度变大,从而加剧大型车辆与小型车辆间相容性变差。相关文献指出,车辆前部在碰撞中产生破坏力的最大值与试验车的自身质量成正比。通过已有的碰撞数据,确定了车辆NCAP等级与乘员死亡率的关系。     

行人碰撞腿部保护研究

本文从生物力学角度综合分析了行人与车辆碰撞过程中其腿部的伤害机理,并根据EEVC行人碰撞保护试验法规建立了腿部撞击器的有限元模型.利用该数值模型,本文针对某国产轿车进行了行人腿部保护的相关研究,并提出了相应的结构改进方案.计算结果表明,通过对保险杠的结构改进可以有效地减轻车辆对行人腿部的伤害,具有较高的可行性.     

斜碰撞再现反推算法研究

结合近年来积累的交通事故调研经验,通过建立轮胎侧偏特性模型、四车轮车辆运动仿真分析模型,解决车辆轮胎印迹内的垂直载荷分布不同的问题,以及由地面多种因素对车辆运动产生不同影响的问题和车辆本身复杂的受力问题,达到事故再现的目的。通过反推计算车辆在碰撞事故发生时的运动状态,可以科学的再现车辆斜碰撞事故发生的过程,明确当事人的事故责任,提供了重要的参考。最后通过运用车辆碰撞分析软件PC-crash,结合具体的交通事故实例,验证了关于汽车斜碰撞反推计算理论的研究结果在实际的交通事故处理中具有较高的实用性与可靠性。     

高速公路隧道路段交通安全特性研究

基于高速公路隧道运行安全特性,对隧道路段定义进行改进。通过提炼交通事故特性参数对高速公路隧道路段和开放性道路的交通事故率进行对比,并对交通事故时间分布规律、空间分布规律、事故形态分布规律以及事故车型分布规律进行统计分析。研究结果表明,我国隧道路段事故率略高于开放性道路,而且隧道洞外事故率远高于洞内,隧道交通事故形态以追尾、刮擦和撞壁为主,火灾事故率极低,交通事故车型以小客车和大货车为主。     

基于信息融合的轿车碰撞两轮车事故车速分析

在对北京市轿车与两轮车碰撞事故调研分析的基础上,深入分析车辆、路面遗留痕迹特征与汽车碰撞特点之间的联系,选择与轿车碰撞速度相关的人体-风窗玻璃接触、人体及车辆与路面接触的痕迹特征参数,运用人工神经网络方法建立了轿车与两轮车碰撞事故的车辆碰撞速度分类预测模型.该模型融合了人-车-路相互作用的痕迹特征信息,采用实际事故案例提取的可靠样本对其进行训练并应用于车速估算.     

山区公路小半径弯道路段事故严重度影响因素及其异质性比较分析

为分析影响山区公路小半径路段典型事故的严重程度的相关因素及其异质性效应，基于某山区双车道公路1 067起交通事故数据，从驾驶员、车辆、道路和环境4个方面选取15个潜在特征变量，采用二项Logit模型和随机参数二项Logit模型，分别构建小半径弯道路段上追尾碰撞、正面碰撞和侧面碰撞3类典型事故的严重度分析模型，分析3类典型事故严重度的显著影响因素，并采用边际弹性系数量化分析影响因素的作用强度。结果表明，小半径弯道路段上不同形态事故的严重度影响因素存在明显差异:①追尾碰撞严重度的显著影响因素依次为摩托车、夜间、弯道转角、驾驶员年龄、季节，摩托车和冬季分别是服从(2.716.1.5642)和(-1.495，2.1162)正态分布的异质性影响因素，导致发生伤亡事故的概率为95.72%和23.58%；②正面碰撞严重度的显著影响因素依次为货车、摩托车、驾驶员超车、弯道转角和弯道长度，货车导致其伤亡事故概率增加108.8%，摩托车和弯道长度分别是服从(6.941，9.9012)和(-0.004，0.0032)正态分布的异质性影响因素，导致发生伤亡事故的概率为76.11%和9.18%；③侧面碰撞严重度的显著影响因素依次为摩托车、驾驶员年龄及弯道有接入口，摩托车和接入口分别是服从(5.211，5.1112)和(-1.408，2.1462)正态分布的异质性影响因素，导致发生伤亡事故的概率为88.87%和25.47%。④与传统二项Logit模型相比，追尾碰撞、正面碰撞和侧面碰撞的随机参数二项Logit模型的拟合优度分别提高了2.85%，4.15%，6.76%，且定量捕捉了异质性影响因素，更适用于事故严重度的精细化分析。      

从道路交通事故研究看我国汽车正面碰撞法规试验形式

基于我国道路交通深度事故调查中所得数据,从碰撞位置与重叠率、碰撞速度和人员伤亡等方面,分析100%重叠率刚性固定壁障碰撞试验和40%重叠率偏置可变形壁障碰撞试验与我国交通事故形态和人员伤害与特征的关联度.讨论现有正面碰撞法规的试验形式的局限性,并论证了将偏置正面碰撞推荐性标准纳入我国正面碰撞强制性标准体系的必要性和紧迫性.     

The ‘safety in density’ effect for cyclists and motor vehicles in Scandinavia: An observational study

Safety in density (SID) potentially explains the safety in numbers (SIN) phenomenon by positing that ‘the SIN effect can be reproduced simply through encouraging behaviour that leads to the formation of higher-density cyclist groups’. The study further explores this hypothesis using event-based exposure, queues and groups of road users. Using three different definitions of encounters between road users, these were manually counted at signalized intersections, and their relationship to traffic volume was assessed. Based only on the frontmost motor vehicle in a queue and one cyclist among the several passing in front of that vehicle, the results show a less than linear relationship between meetings and traffic volume. An increase in the number of cyclists entails a general increase in cyclists passing in front of each motor vehicle, and an increase in motor vehicles increases queue lengths. However, crash data from the Swedish accident database (STRADA) show that it is exceedingly rare for multiple cyclists to be injured in the same crash. Together with results from a crash-encounter model, this suggests that the SID hypothesis may help to explain SIN     

Road characteristics and environment factors associated with motorcycle fatal crashes in Malaysia

This study aims to determine risk factors contributing to traffic crashes in 9,176 fatal cases involving motorcycle in Malaysia between 2010 and 2012. For this purpose, both multinomial and mixed models of motorcycle fatal crash outcome based on the number of vehicle involved are estimated. The corresponding model predicts the probability of three fatal crash outcomes: motorcycle single-vehicle fatal crash, motorcycle fatal crash involving another vehicle and motorcycle fatal crash involving two or more vehicles. Several road characteristic and environmental factors are considered including type of road in the hierarchy, location, road geometry, posted speed limit, road marking type, lighting, time of day and weather conditions during the fatal crash. The estimation results suggest that curve road sections, no road marking, smooth, rut and corrugation of road surface and wee hours, i.e. between 00.00 am to 6 am, increase the probability of motorcycle single-vehicle fatal crashes. As for the motorcycle fatal crashes involving multiple vehicles, factors such as expressway, primary and secondary roads, speed limit more than 70 km/h, roads with non-permissible marking, i.e. double lane line and daylight condition are found to cause an increase the probability of their occurrence. The estimation results also suggest that time of day (between 7 pm to 12 pm) has an increasing impact on the probability of motorcycle single-vehicle fatal crashes and motorcycle fatal crashes involving two or more vehicles. Whilst the multinomial logit model was found as more parsimonious, the mixed logit model is likely to capture the unobserved heterogeneity in fatal motorcycle crashes based on the number of vehicles involved due to the underreporting data with two random effect parameters including 70 km/h speed limit and double lane line road marking.     

北京市道路交通事故特征的研究

基于交通事故数据,对北京交通事故的时空分布、肇事车辆、死伤人员、事故原因等特征进行研究。结果表明,北京交通事故分布具有规律性,肇事主体以及事故原因具有特殊性。     

Crash analysis and dynamical behaviour of light road and rail vehicles

The main goal of crashworthiness is to ensure that vehicles are safer for occupants, cargo and other road or rail users. The crash analysis of vehicles involves structural impact and occupant biomechanics. The traditional approaches to crashworthiness not only do not take into account the full vehicle dynamics, but also uncouple the structural impact and the occupant biomechanics in the crash study. The most common strategy is to obtain an acceleration pulse from a vehicle structural impact analysis or experimental test, very often without taking into account the effect of suspensions in its dynamics, and afterwards feed this pulse into a rigid occupant compartment that contains models of passengers. Multibody dynamics is the most common methodology to build and analyse vehicle models for occupant biomechanics, vehicle dynamics and, with ever increasing popularity, structural crash analysis. In this work, the aspects of multibody modelling relevant to road and rail vehicles and to occupant biomechanical modelling are revised. Afterwards, it is shown how multibody models of vehicles and occupants are used in crash analysis. The more traditional aspects of vehicle dynamics are then introduced in the vehicle models in order to appraise their importance in the treatment of certain types of impact scenarios for which the crash outcome is sensitive to the relative orientation and alignment between vehicles. Through applications to the crashworthiness of road and of rail vehicles, selected problems are discussed and the need for coupled models of vehicle structures, suspension subsystems and occupants is emphasized.     

Evaluation of risk factors for road accidents under mixed traffic: Case study on Indian highways

This paper presents an evaluation of risk factors for highway crashes under mixed traffic conditions. The basis of selecting study sites was abutting land use, roadway, and traffic characteristics. Accordingly, the study selected thirteen segments on the existing highway network in the state of West Bengal of India, covering a wide spectrum of such road attributes. A systematic investigation based on site-specific accident data to capture the highway sections' safety features revealed that the crash rate has steadily increased for years with traffic regardless of roadway category and conditions. A number of risk factors that affect road accidents were identified; they are mid-block access, pavement and shoulder conditions, vehicle involvement, time of day, and road configuration, i.e., two and multi-lane. The empirical observation indicates that the crash rate is relatively lower on multi-lane highways; however, the severity of any crash on such a road is relatively high. Notably, the crash frequencies on such roads are less during daylight hours due to the lane-based unidirectional traffic movement. This is quite the opposite during nighttime when drivers exhibit an inability to meet traffic contingencies, thereby increasing crash risk. The majority of crashes on two-lane highways are, on the other hand, due to unsafe driving manoeuvers. The study also observed that frequent mid-block accesses and poor shoulder conditions reduce scopes to rectify driving errors and increase crash risk as a consequence. The paper subsequently suggests proactive approaches to identify safety deficits at the time of planning and designing.