新型波形梁护栏端头的设计及其正面碰撞仿真分析

汽车与路侧护栏端头相撞是极其危险和复杂的事故。本文提出了一种新的波形梁护栏端头结构,利用PRO/E和ANSYS软件建立了波形梁护栏端头受冲击荷载作用的有限元模型,并对其进行了合理性的模拟仿真检验。研究结果表明：新的护栏端头结构具有较好的吸能效果和良好的可靠安全性,可吸收汽车-护栏碰撞过程中的大部分能量,在很大程度上避免了护栏端头插入车厢内部等严重情况的发生。     

Decision aid for allocation of transportation funds to guardrails

We address the need for allocation of resources to run-off-road and fixed-object hazards on immense secondary road systems. In Virginia, there are 95,000km of roadway with uncharacterized hazards in need of guardrail upgrade, installation, or related warning signs or other protection. A decision aid is developed to assist the planner in guardrail resource allocation by accounting for the potential crash severities, traffic exposures, costs of treatment, and other factors. A premise is that no single benefit-cost ratio or selection criterion applies across all localities. The decision aid enables the planner to interpret the variety of benefits and costs in their own units, emphasizing the needs and preferences of individual localities. The paper describes: (1) archiving and comparison of protected and unprotected hazards; (2) regional screening of hazardous corridors and (3) multicriteria benefit-cost analyses of guardrail sites. A case study of guardrail selection is presented.     

水泥厂窑尾塔架防护栏杆的设计优化探讨

防护栏杆作为建筑物的附属构件,虽不影响主体结构的受力性能,却对保障使用者的生命财产安全起着重要的作用。本文以某5000TPD规模窑尾塔架为例,对其主楼层和钢平台、钢梯的防护栏杆选型进行对比;在安全适用的前提下,尝试对标准图集02(03)J401对栏杆构件设计优化。本次设计优化未能取得预期的效果,仅仅统一了栏杆风格,但对任意改变构件大小的行为可以起到警示作用。     

Effect of shoulder width, guardrail and roadway geometry on driver perception and behavior

Roadway design is one of the most significant factors that affect driving behavior and perceived safety. The current study tests the combined effects of three roadway design elements – shoulders width, guardrail existence and roadway geometry (curvature) – on objective driving measures (speed and lane position), and subjective measures (perceived safe driving speed and estimated road safety).Twenty two drivers participated in an experiment with a driving simulation. In the first part objective driving data were collected, and in the second part subjective paper–pencil evaluations were requested of the perceived safety of 30 different scenarios that were previously experienced in the simulator. The scenarios consisted of the various combinations of the three roadway design elements.The results showed a significant effect of roadway geometry on both objective and subjective measures. The shoulders width had a significant effect on actual speed, on lane position, and on perceived safe driving speed, but only when a guardrail was present.These findings illustrate the perceptual role of a guardrail in defining the perceived safety margins that various shoulder widths provide. When a guardrail is absent, the width of the shoulder loses much of its benefits and effects on driving behavior. The results also demonstrate that roadway geometry can be used to reduce driving speeds, but at the same time it can have a negative effect on maintaining a stable lane position in sharp curves. Thus, controlling the width of road shoulders and the placement of guardrails seems to be a safer approach to speed and lane position control.     

高／快速路立交低光照明应用分析

针对高／快速路立交范围采用传统的路灯、高杆灯照明方式和采用低光照明方式进行分析和评价,并根据低光照明基本结构和特点,提出高／快速路立交建设中采用低光照明具有较大的实用价值。     

焊管企业生产高速公路护栏板和立柱的前景展望

随着我国高速公路的迅速发展, 作为高速公路交通安全设施重要组成部分的护栏板和立柱需求量将大幅增加。焊管企业生产此种产品有着明显的优势, 只需少量的投资即可投入生产。这样既可以充分发挥焊管生产设备的潜力, 又可以提高企业的经济效益。     

有限元计算在护栏设计和乘员保护中的应用

目前，汽车-护栏碰撞研究的主要方法还是实车足尺寸实验，但是这种方法实验周期长，费用昂贵。仿真的方法可以花费很少的资金来完成不同参数下的碰撞研究。该文通过LS-DYNA建立轿车-护栏的碰撞仿真系统，基于这样的系统进行轿车-护栏的碰撞性能研究，对那些会显著影响护栏性能的参数进行了分析。结果表明，有限元仿真是进行汽车护栏碰撞研究的有效方法。     

卷板式护栏端头正面碰撞分析

为了解卷板式护栏端头安全性能,本文建立有限元仿真模型,运用碰撞试验对仿真模型进行可靠性验证后,对卷板式护栏端头进行正面碰撞分析。结果表明:仿真与碰撞试验结果相符,验证了仿真方法的可靠性;不同速度正面中心碰撞,端头卷板吸能效果良好,但加速度峰值随速度增加有较大增加;不同角度正面碰撞,车辆姿态良好,加速度峰值变化不大;不同位置正面碰撞端头,端头吸能效果良好,加速度峰值变化不大;卷板器质量是加速度峰值产生的最主要因素。卷板式端头可有效降低事故严重程度,保护乘员安全。     

Fatality risk in motorcycle collisions with roadside objects in the United States

Motorcycle crashes with roadside objects often involve more than one impact event: typically involving a collision with the ground and another object. The objective of this study was to determine the fatality risk in these roadside object collisions when compared with crashes only involving a collision with the ground. The roadside objects analyzed included guardrails, concrete barriers, signs, utility poles, and trees. The Fatality Analysis Reporting System (FARS) database was used in conjunction with the General Estimates System (GES) to analyze fatality risk for motorcycle crashes from 2004 to 2008. The analysis was based upon over 3600 fatal motorcycle crashes with roadside objects. Collisions with roadside objects were found to have a higher fatality risk than collisions with either the ground or another motor vehicle. Based on the most harmful event reported in the crash, motorcycle collisions with guardrail were 7 times more likely to be fatal than collisions with the ground, and collisions with trees were almost 15 times more likely to be fatal than collisions with the ground. Additionally, the roadside object was reported as the most harmful event in the majority of the crashes in fatal two-event crashes involving a roadside object and a collision with the ground, with the exception of collisions with signage. From these analyses it was concluded that collisions with fixed objects are more harmful to motorcyclists than collisions with the ground.     

Guardrail influence on pedestrian crossing behavior at roundabouts

Pedestrians account for 10–30% of all road accident fatalities in western countries, and therefore efforts to improve pedestrian safety are of major importance. Research can support these efforts in various ways, particularly by studying road crossing patterns, and by exploring pedestrian compliance rates to safety laws and guidelines.