Research On Anti-skid Warning Of Passenger Cars On Wet Slippery Pavement

Rain falls on the road surface and is eliminated by road surface runoff.It is easy to form a layer of water film on the road surface,reduce the road surface adhesion coefficient,and easily cause the phenomenon of tire water skiing.Since the last century,the tire water skiing has also experienced from basic experiments to finite element research.However,due to the complexity of road surface water film and vehicle tire,how to accurately analyze road surface water film and tire water skiing is still an urgent problem to be solved,even when the computer simulation technology is mature today.Firstly,the factors that influence the thickness of the surface water film under the condition of rainfall were discussed in this paper.And the factors mainly include the length of the road slope,the gradient of the road,the depth of the pavement structure and the rainfall.Especially for the influence of the length of the road slope,the longitudinal length of the slope was calculated according to the design requirements of the expressway,and the flow pattern of the surface water film of the expressway was determined to be turbulent according to the critical Reynolds number.The data in this paper was optimized based on the experimental data of Ji Tianjian’s simulating rainfall,and the prediction model of surface water film thickness was established by multiple regression model,then the regression equation and regression coefficient were tested for significance to prove that the impact is significant.Secondly,on the basis of considering the tire market penetration rate,the representative tire was selected and the radial tire finite element model with longitudinal and transverse decorative patterns was established.The tire model was obtained by the way of joint fixation of the interface after the tire pattern and main body are modeled respectively.The tire rubber material is simulated by Yeoh super elastic material after analysis,and the rubber-cord composite material is simulated by stiffener element.The radial stiffness of the tire model was verified,and it was proved that the tire model is similar to the actual tire performance.Then,the finite element model of tire water skiing was established,and the relationship between tread depth,water film thickness,vehicle speed and hydrodynamic pressure was obtained through the Fluent software for simulation experiment.And then,the critical tire water skiing speed was calculated according to tire load and hydrodynamic pressure,and the verification of critical water skiing speed was completed by using the integrated driving data of rainy days.Finally,according to the research results of the prediction of water film thickness on the road surface and the critical water speed of the tire in this paper,the demand analysis and the working logic design of the tire water skiing early warning were carried out,and the design of the tire water skiing early warning system was finally completed,which provides a guarantee for the safe driving in rainy days.