An Optical-Based Technique to Obtain Vibration Characteristics of Rotating Tires 10-03-03-0013

The dynamic characteristics of tires are critical in the overall vibrations of vehicles because the tire-road interface is the only medium of energy transfer between the vehicle and the road surface. Obtaining the natural frequencies and mode shapes of the tire helps in improving the comfort of the passengers. The vibrational characteristics of structures are usually obtained by performing conventional impact hammer modal testing, in which the structure is excited with an impact hammer and the response of the structure under excitation is captured using accelerometers. However, this approach only provides the response of the structure at a few discrete locations, and it is challenging to use this procedure for rotating structures. Digital Image Correlation (DIC) helps in overcoming these challenges by providing the full-field response of the structure. Although there have been many experiments on tires, there are few published papers that investigate the full-field dynamics of rotating tires at high rotating speeds. In the current work, the Kettering University Formula SAE (FSAE) vehicle is loaded on a chassis dynamometer for the purpose of performing a tire experiment. A pair of high-speed cameras capture high-resolution images to obtain the response of the tire sidewall in stationary and rotating conditions. The modal characteristics of the tire are obtained by processing these images. The results reveal the resonant frequencies and the operational deflection shapes of the loaded and unloaded tire in stationary and rotating conditions. The current article provides full-field information about the dynamics of tires at high rotating speeds for engineers and scientists in the field.