A simulation based large bus side slip and rollover threshold study in slope-curve section under adverse weathers.

Lin Tian,Jueshuai Li,Yanfei Li,Wenzhen Lv,Feng Chen

doi:10.1371/journal.pone.0256354

Abstract

To study the side slip and rollover threshold of large bus in slope–curve section under adverse weather, factors that affect the safety of large buses that run in slope–curve section, such as rain, snow, cross-wind environmental factors, and road geometry, were analyzed to obtain the friction coefficient of the road surface under different rainfall and snowfall intensities through field measurements and to determine the six-component force coefficient of wind that acts on large buses through wind tunnel tests. The force analysis of large bus in slope-curve section was carried out, and the mechanical equations of large bus under the limit conditions of sideslip and rollover in slope-curve section were established. TruckSim simulation test platform was used to establish a three-dimensional road model and large bus mechanical model at a design speed of 100 km/h. Input parameters, such as cross-wind speed and road friction coefficient, simulate the impact of wind-rain/snow coupling. Under the combined action of wind-rain/snow, the operation test of large bus in slope-curve section was carried out, and the key parameters and indicators of the sideslip and rollover of large bus in slope-curve section were outputted and analyzed. The sudden change point of lateral acceleration is the judging condition for sideslip of large bus in slope-curve section under different road friction coefficient (0.2–0.7), changing from 0.15m/s2 and stabilizing to 0.52 m/s2, and a 0N vertical reaction force of the inner tire is the critical judging condition for rollover under road friction coefficient0.8, and the operating speed thresholds were proposed under different road friction coefficient. This study is expected to provide theoretical support for the speed limit of large bus in slope-curve section under adverse weather.

Highlights

In the statistics of road traffic accidents, the proportion of traffic accidents caused by large buses is increasing, and the fatalities and property losses caused by large buses are huge
Large bus side slip and rollover threshold study in slope-curve section under adverse weathers accident statistics, the total number of deaths due to large bus accidents each year accounts for 65% of the total number of deaths from all vehicle-related accidents, and the proportion of fatalities caused by the sideslip and rollover of large passenger cars on curved and sloped road sections is 45% [1, 2]
Through the TruckSim simulation test, the critical condition for judging the sideslip of the large bus in the slope–curve section is determined to be the lateral acceleration sudden change point, and the critical condition for the rollover is that the vertical reaction force of the inner wheel is reduced to 0 N

Summary

Introduction

In the statistics of road traffic accidents, the proportion of traffic accidents caused by large buses is increasing, and the fatalities and property losses caused by large buses are huge. Large bus side slip and rollover threshold study in slope-curve section under adverse weathers accident statistics, the total number of deaths due to large bus accidents each year accounts for 65% of the total number of deaths from all vehicle-related accidents, and the proportion of fatalities caused by the sideslip and rollover of large passenger cars on curved and sloped road sections is 45% [1, 2] These traffic accident cases show that large bus are prone to rollover traffic accidents in slope-curve section that cause heavy casualties and property losses. Under the influence of adverse weather, wind, rain, and snow, the risk of side slip and rollover accidents of large bus in slope-curve section has increased. The operation safety of large bus in slope-curve section under adverse weather needs to be solved urgently

Results

Discussion

Conclusion