HEAVY VEHICLE DESIGN PARAMETERS AND DYNAMIC PAVEMENT LOADING

This paper presents preliminary results from ARRB project 387: Whole Vehicle Dynamics Affecting Dynamic Pavement Loading. The aims and modelling approach of the project are described. Comparisons between model predictions and experimental data are made, showing reasonable agreement. The effects of various parameter changes, such as centre of gravity location, distribution of sprung mass, speed, roughness scale, as well as suspension stiffness and damping, are investigated. The direction for future work in this project is outlined. Model predictions indicate that whole vehicle configuration has an important effect on the level of pavement loading. It is therefore concluded that pavement-protecting guidelines for vehicle suspension selection should have regard to overall vehicle configuration. The form of calculated speed-load relationships is complicated and variable between vehicles, which indicates that the pavement damaging effect of a particular vehicle should be assessed over a speed range rather than at just one or two speeds. It is predicted that the dynamic loading level of vehicles fitted with tandem suspensions which provide only poor damping of pitch motions will be high over certain speed ranges, but that these high levels will be significantly reduced when shock-absorbers are fitted between the chassis and axles. (Author/TRRL)