3D Modal Analysis of a Loaded Tire with Binary Random Noise Excitation

Modal analysis of tires has been a fundamental part of tire research aimed at capturing the dynamic behavior of a tire. An accurate expression of tire dynamics leads to an improved tire model and a more accurate prediction of tire behavior in real-life operations. Therefore, the main goal of this work is to improve the tire-testing techniques and data range to obtain the best experimental data possible using the current technology. With this goal in mind, we propose novel testing techniques such as piezoelectric excitation, high-frequency bandwidth data, and noncontact vibration measurement. High-frequency data enable us to capture the coupling between the wheel and tire as well as the coupling between airborne and structure-borne noise. Piezoelectric excitation eliminates the dynamic coupling of shakers and the inconsistency of force magnitude and direction of impact hammers as well as added mass effect. Noncontact vibration measurements using three-dimensional (3D) scanning laser Doppler vibrometer (SLDV) are superior to accelerometers because of no mass loading, a high number of measurement points in three dimensions, and high sensitivity. In this work, a modal analysis is carried out for a loaded tire in a static condition. Because of the highly damped nature of tires, multiple input excitation with binary random noise signal is used to increase the signal strength. Mode shapes of the tire are obtained and compared using both accelerometers and SLDV measurements.