Design of a Lab-scale Tyre Wear Test Rig

Abstract

Tire wear particles are recognized as one of the primary sources of microplastics in the environment, with documented impacts on air and water quality and human health. Growing regulatory attention at both European and international level makes the study of their generation an increasingly relevant and urgent research topic. This thesis investigates the feasibility of a lab-scale tire test rig designed for the generation and collection of tire wear particles, with the aim of understanding the associated design requirements and estimating the manufacturing costs. The machinery accommodates real tires interacting with asphalt specimens, and the contact geometry represents a compromise between those of the most widely adopted large-scale test rigs. The work is structured around three main contributions. First, a review of existing large-scale tire test rigs is presented, providing the design basis and benchmarking criteria for the proposed solution. Second, tire dynamics are analyzed in depth, with particular focus on the turn slip condition, which characterizes the kinematic configuration resulting from the chosen contact geometry, namely the flat rotating disk. Third, the actuator sizing is carried out based on theforces generated at the contact patch, followed by the detailed design of the two main subassemblies: the disk assembly and the tire-side assembly. The final solution integrates a quarter-vehicle mounted on a 4-column frame, which enables thevertical travel of the tire assembly and its loading against the flat rotating disk. Throughout the design process, two guiding principles were consistently pursued: cost reduction, achieved through the selection of standard off-the-shelf components and custom parts manufacturable from common semi-finished products via conventional processes such as welding, milling, drilling, and turning; and modularity, conceived so that individual units and sub-assemblies can be independently replaced or improved in future developments. However, the disk radius, which must be large enough to limit the turn slip component, drives both the overall dimensions and the costs of the machinery upward. Furthermore, the solution cannot be dispensed within inherently complex systems, including the actuation and control system, and the construction of dedicated foundations capable of accommodating the different levels of the sub-assemblies and, most importantly, of transferring significant loads to the ground. Within these constraints, the proposed design represents a sound feasibility study and a viable basis for the future manufacturing of the test rig.