Dynamic Characteristic Analysis Of Vehicle-Road Coupled System Considering The Factor Of Pavement Evenness

Dynamic vehicle-roads interaction is a new research subject, at the meantime, it is also a complex subject which involves the fields of road engineering and vehicle engineering.Considering the factor of pavement evenness, this paper has made a theoretical analysis on the coupled vibration of vehicle and road. Firstly, by simplifying the vehicle to a two DOF vibration system, dispersing road as a multi-layer FEM system, considering the road and vehicle as a whole system, and using the condition of compatible displacement of tire and pavement, the vibration equations of vehicle and road are related, the dynamic coupled equation of vehicle-road system is deduced, and then an expression of dynamic load is given. Secondly, the dynamic coupled equation is solved by the method of the combination of Newmark-βand Newton - Raphson iteration, and a solving program is developed by VB programming language ; Finally, this paper selects two vehicle model and one road structure, analyses the effect of road and vehicle parameter variety on dynamic properties of vehicle-road system, and then using the random dynamic loads, a transient dynamic analysis of road structure is carried on.The calculating result indicated that when the pavement evenness becomes worse, vehicle dynamic amplification factor and the Root Mean Square value of vehicle body vibration acceleration are increasing greatly, the proportion of larger dynamic value and the probability of vehicle jumped out of ground are growing too. With the increase of vehicle speed, vehicle dynamic amplification factor, the proportion of larger dynamic value and the probability of vehicle jumped out of ground are growing, the Root Mean Square value of vehicle body vibration acceleration is fluctuating. It also shows that the alternative variation of tensile-compressive stress is one of the most important factor in the fatigue damage of road structure. While the overloading vehicles running on the road, the stress in the road structure will become larger, and it will also reduce the fatigue life of the road.This recognition will provide some valuable references for us on the study of road design, operation, maintenance, and fatigue failure in future.