Modeling and analytical calculation of road damage coefficient considering tire pressure and damping of vehicles

Abstract

The road damage coefficient [Formula: see text] is a significant indicator to estimate the degree of the road damage caused by vehicles. The existing calculation method of [Formula: see text] is not convenient for the engineering application. To effectively evaluate the damage degree and facilitate the engineering application, this paper studied the simple and reliable analytical calculation method of [Formula: see text]. Firstly, a dynamic model of the vehicle–road system was created. The tire pressure and the tire damping were considered in the model. Moreover, the relationship between the tire vertical stiffness and the tire pressure is approximated as a linear function. Secondly, based on the dynamic model, according to the definition of [Formula: see text], a concise analytical formula of [Formula: see text] was derived and verified by numerical simulations. The relative errors of the analytical calculation results are all less than 0.1%. Thirdly, the influences of the tire pressure [Formula: see text], the damping ratio [Formula: see text] of the suspension system, and the damping ratio [Formula: see text] of the wheel system on [Formula: see text] were analyzed. Moreover, based on the analytical formula of [Formula: see text], a mathematical model of the optimal damping matching for the suspension system was established and a case study was also given. The research results show that the larger the tire pressure [Formula: see text], the larger the value of [Formula: see text] is. For each [Formula: see text], there is an optimal damping ratio [Formula: see text]. If the tire damping is ignored, it will lead to the design error for [Formula: see text]. Finally, some important conclusions were drawn. The analytical formula of [Formula: see text] and the conclusions can provide valuable references for the analysis of the road damage and the initial design of vehicle suspensions.