Vibration Modes of Radial Tires: Measurement, Prediction, and Categorization Under Different Boundary and Operating Conditions

The use of tire vibration modes to represent dynamics in tire models has grown significantly over the years. Initially used primarily in tire modal models to simulate low- to mid-frequency range structure-borne Noise, Vibration, and Harshness (NVH), the applications have broadened to higher frequency, air-borne NVH, and more recently to durability, ride, and braking performance simulations. The broadness and growing importance of these applications lend to having a unified understanding of tire modes and their significance to simulation quality. To this end, a naming convention using wave numbers is developed to identify and categorize modes of an unloaded tire. Background on measurement and predictive tools is presented. Finite element method models are used for interpreting the wave number concept to the 3-D mode shapes and to account for dynamics of the wheel and enclosed air cavity. The effect of tire construction changes on families of modes is discussed throughout. The intent is to simplify and improve identification and physical understanding of tire vibration modes, measurement and simulation techniques and quality, and communication among NVH specialists as well as non-NVH analysts.