All Title Author
Keywords Abstract

-  2018 

路面薄水膜状态对行车安全的影响
Influence of thin water films over road surfaces on driving safety

Keywords: 交通工程,交通安全,临界水膜厚度,摩阻系数,路面薄水膜状态,水膜厚度,路面构造深度
traffic engineering
,traffic safety,critical water film thickness,skid resistance coefficient,road surface thin water film,water film depth,road surface microtexture

Full-Text   Cite this paper   Add to My Lib

Abstract:

为研究降雨天气下路面薄水膜状态对行车安全性的影响机理,通过借鉴斯特里贝克曲线中关于流体润滑状态的描述,认为存在薄水膜的轮胎与路面之间的关系符合该曲线中的典型状态。基于此,可通过测试薄水膜状态下路面摩阻系数的变化,来反映车辆在有水膜的湿滑路面行驶中轮胎与路面之间的接触状态。采用动态摩阻系数测试仪,针对3种不同构造深度的典型路面试件,开展不同水膜厚度下的动态摩阻系数测试试验,基于试验观测数据,建立不同滑动速度下水膜厚度对应的动态摩阻系数非线性回归模型,并绘制了模型曲线。基于模型曲线,提出了影响行车安全的临界水膜厚度的概念及取值,以临界水膜厚度来反映轮胎在水膜路面行驶中从混合润滑到流体动力润滑的过程。结果表明:当滑动速度分别为20、40、80 km/h时,临界水膜厚度分别为0.48、0.44、0.39 mm;在速度一定时,当路面水膜厚度超过临界水膜厚度,黏性水滑发生的风险显著增加;受薄水膜影响,路面构造深度越小,摩阻系数下降越快,摩阻系数值也降的更低;在受降雨影响较严重的地区,路面构造深度越高的路面类型,即采用粗集料的路面,更有利于轮胎与路面之间水膜的排出,从而提高车辆在薄水膜状态下的行车安全性。
The influence of a thin water film on traffic safety under rainfall was studied. By referring to the description of fluid lubrication in a Strybeck curve, the relationship between the tire and road surface with a thin water film was considered to conform to the typical state of a curve. Based on this, the contact between the tire and road surface when driving on wet pavements with a water film can be reflected by testing the change in the road surface friction coefficient under the state of the thin water film. Using a dynamic friction coefficient tester, the dynamic friction coefficient of different water film thicknesses was tested on three typical road surface test pieces with different texture depths. Based on the experimental observation data, a nonlinear regression model of the dynamic friction coefficient corresponding to the water film thickness at different sliding speeds was established, and a model curve was drawn. Based on this model curve, the concept and value of the critical water film thickness affecting driving safety were proposed. The critical water film thickness was used to reflect the approaching process from mixed lubrication to hydrodynamic lubrication of the tire on a road surface with a water film. The test results show that when the speed is 20, 40, and 80 km/h, the critical water film thickness is 0.48, 0.44, and 0.39 mm, respectively. At a certain speed, when the surface thickness of the water film exceeds the critical water film thickness, the risk of a viscous water slip significantly increases. Under the influence of a thin water film, the smaller the pavement structure depth, the faster the decrease in friction coefficient, and the lower the friction coefficient. In areas where rainfall has a more severe effect, pavement types with higher texture depth (pavements with coarse aggregate), can be more advantageous to the discharge of the water film between the tire and road surface, thus improving driving safety under the presence of a thin water film. 2 tabs, ??8 figs??, 28 refs.?

Full-Text

comments powered by Disqus

Contact Us

service@oalib.com

QQ:3279437679

微信:OALib Journal