Numerical sound prediction model to study tyre impact noise

Abstract

Impact noise is one of the mechanisms of vibratory origin that constitutes tyre/road interaction noise. When assessing a vehicle as a noise source, the impact sound mechanism is especially significant when obstacles are present on the driving surface. This document aims to enhance understanding of the impact noise phenomenon by presenting a two-step numerical model for studying the sound propagation of an accelerated tyre impacting a flat, rigid, and reflective surface: Firstly, a dynamic analysis of the contact is performed using the Finite Element Method. Then, the Boundary Element Method is used to perform an acoustic analysis with the vibration of the tyre surface as the sound source. The model has been successfully validated through a drop-test, where a tyre/rim assembly is dropped onto a ground surface. The validation was determined by comparing the predicted Sound Pressure Level measurements to those obtained from a circular microphone structure at various points during the drop-test.