Tire Rolling Resonance from Cleat Impact 2007-01-1529
Tires are the only load path between the road and the vehicle's suspension and so play a key role in determining vehicle NVH performance. Tire structure and behavior include many nonlinear phenomena, such as rubber material response to load, tire contact patch conformity with road profile, and bulging of side walls. In addition to structural nonlinearities, the tire's rotational motion introduces nonlinear resonances that are dependent on vehicle speed, and also rotationally induced harmonics. When a tire rolls over a cleat, the rolling resonance at the spindle may vary with the vehicle's speed. Since tire behavior couples several nonlinear parameters, a numerical tire model that can consider physical characteristics such as, rolling resonance dependence on speed and the harmonic resonances, will definitely be helpful for improving vehicle NVH quality.
This paper presents a study of a finite element tire model rolling over an impact cleat at different speeds. A transition pattern of a rotation wave along the side wall was observed to be related to the tire's rolling speed range. The rolling resonance after impact showed dependence on the traveling speed. The phenomenon of speed dependence was similar to published test data. The wave pattern with circular nodal line characteristics was observed to travel in the opposite rotational direction of the tire's physical movement when rotating at higher speeds.