As internal combustion engines are replaced by quieter electric motors in ground vehicles, noise and vibration sources aside from the powertrain have become relatively more important. This is especially true of tires. Measurement of the dynamic vibratory characteristics of tires is critical to understanding their influence on the noise and vibration performance of vehicles, both outside the vehicle body and inside of it. In this work, the normal modes and operating deflection shapes of a Yokohama Geolander A/T light truck tire are measured using traditional modal analysis techniques as well as a non-contact Scanning Laser Doppler Vibrometry (SLDV) approach. Boundary conditions including free, fixed, loaded, and rotating are implemented to the tire and investigated. Rotating conditions are accomplished in a physical chassis dynamometer environment, with the measured tire mounted on the front axle of a Chevrolet Silverado 1500 pickup truck. Modes of vibration and associated natural frequencies that are measured in all four boundary conditions, including steady-state rotation, are reported and illustrated. Results of the study show that operating deflection shapes of a rotating light truck tire can be measured on a chassis dynamometer using SLDV, assuming the tire is undergoing steady-state rotation, but certain disadvantages in the dynamometer environment make the measurement procedure challenging. Specific concerns such as tire rotating speed consistency and sufficient spatial and frequency resolution of the measurements are delineated in this work. Moreover, practical recommendations for measurement of rotating tire operating deflection shapes using a SLDV are included, and a comparison with the Digital Image Correlation (DIC) method of measurement is presented.
Bastiaan et al. (Tue,) studied this question.