Abstract
Accelerated Pavement Testing (APT) facilities are nowadays considered fundamental for the thorough understanding of the performance of pavements. The amount of information that can be derived from APT investigations can serve as the basis for a more performance-related pavement design but also for the development of new pavement types and innovative materials. In the design and use of such facilities, special care should be placed in the modeling of the loading systems which are employed to produce accelerated damage. Such an analysis is important both in the preliminary design phase, in which technological solutions are found in order to simulate the effects of heavy vehicles on the pavement, and in the various phases of investigation, when the recorded damage has to be clearly related with effective loading conditions. In this respect, modeling can be a valuable support to the evaluation of the data which can be acquired by means of a proper instrumentation of the facility. In order to address such issues, the Authors have developed a design procedure which together with typical stationary calculations includes the adoption of Multi-Body (MB) and Finite Elements (FE) models of the testing system. As proven by the first implementation exercises of the design procedure, the use of MB and FE models allows the evaluation of the dynamics of the system in a wide variety of testing conditions. Thus, stresses and strains in the structure of the APT facility can be estimated and the dynamic forces and torques which arise during testing at the tire-pavement interface can be predicted. Given the width of the design problem, this paper gives only a general overview of the structure of the proposed procedure, with its application to a specific case which has been studied in depth. Refinements are still under way and will hopefully yield a set of modeling methods which in the future will be available for the design of new APT facilities and for the assessment of the performance of existing systems.