Numerical Modelling of Stone Lofting by a Treaded Tyre 2024-26-0270

In passenger cars, exterior damage due to external objects is a common and repetitive problem for the costumer. A vehicle running over an unpaved or granular road undergoes such damages where the tyre picks up stones (Figure 1) [1] and ejects them towards the vehicle exterior surfaces. These stones cause mechanical damage to the vehicle: affecting aesthetics, accelerating corrosion, and reducing safety. This mechanical damage is more severe in case of electrical vehicles as batteries are placed at the underside of the vehicle. Figure 2 [2] shows an example damaged caused by stone chipping. Induced erosion due to chipping cause corrosion propagation on the peeled surface, Figure 2 shows an example of such corrosion. So far, physical testing and analytical mathematical methods are the most common ways to evaluate damages. However, there is a need of computationally inexpensive, repeatable, and accurate method, which can account for the complex system. This paper describes a validated Multiphysics numerical model for stone lofting, using a stand- alone all-weather tyre. The presented Multiphysics model couples Discrete Element Method (DEM), Finite Element Method (FEM), Multi-body Dynamics (MBD). Results of this work correlate well with experimental findings from Andreas Schönberger [3]. These experiments were performed in a controlled environment with a standalone treaded tyre and for three different velocities of 30kmph, 50kmph and 80kmph which accounts for tyre rotation. The results presented in this work show that method used is capable to capture relevant physics and predict stone lofting numerically. This method is anticipated as a starting point for the development of more sophisticated numeric models for stone chipping prediction.