The Study About Road Friendliness Characteristic Basing On Vehicle-road Coupled System

At present the study of the vehicle, road, and the interaction between the two dynamic problems are still small. To carry out the study of the vehicle-road dynamic interaction, in order to provide a reference for the design of friendly road is an important research work.In this paper, giving full consideration to the vehicle-road whole system, then establishing the vehicle model and the road model to analyses the dynamic coupling of vehicle and road.â‘ The 1 / 2 vehicle vertical vibration model and dynamic equations are established, in considering the body vertical vibration, body vertical rotating, non-suspension of the vertical vibration, as well as the wheel. Through the compatible displacement of tire and road surface conditions, the vehicle and road equation are linked to reflect the vehicle-road systemic dynamic coupling equations.â‘¡Developed a numerical simulation program for vehicle-road coupled dynamic analysis. Made a large number of calculations analysis from a variety of different conditions as the road structure, road roughness, road material parameters, speed changes and so on, by the road friendly point. Analysis of the changes in the vehicle-road system parameters impact on various assessment indicators, for example, the vehicle body acceleration, vehicle dynamic load and load rutting coefficient, and so on.â‘¢The study found that under the same conditions the asphalt concrete pavement is more easily lead to vehicle vibration than the cement concrete pavement, but the structure type has small impact on dynamic load; The lower surface roughness, the impact of traffic characteristics is greater, the road-friendly features are lower; Changes in vehicle speed have a greater impact on vehicle dynamic load factor and vehicle body acceleration, as the speed increases, dynamic load factor also increased; The value of maximum deflection in the surface of the road surface of the road structure, and the deflection value decreases with increasing depth; The structure layer of road's horizontal stress is alternating, the surface layer bear the compressive stress, the maximum compressive stress appears in the asphalt surface layer of the surface, the maximum tensile stress appears in the sub-base junction with the embankment; the vertical dynamic strain of the surface of the asphalt surface layer is alternating, the first pull-back pressure effect of the vertical dynamic strain makes the asphalt surface be easily generated from the grass roots, causing the surface of the slip road damage; In the asphalt surface layer, shear stress increases with depth faster ,the shear stress in the surface is small, then increased rapidly and at the bottom of the asphalt surface reached the maximum shear stress.