Vibration testing of tires by multiple excitations coupled with velocity feedback control

This study aims to develop a multiple excitation system that improves the identification of modal parameters for the vibration testing of tires. Rubber, the main tire material, shows high damping characteristics. Therefore, the resonance peaks broaden, and it is difficult to identify the modal parameters. In the equations of motion, the damping force is proportional to the velocity of the equivalent mass and acts in the opposite direction of motion. This study proposes a novel multiple excitation testing method using velocity feedback control to counteract the damping force. The proposed method provides frequency response function (FRF) data with peak shapes. Three shakers were used to excite an automotive tire, and they were driven with forced vibration and velocity feedback signals. Using the proposed method resulted in shaped resonance peaks of the FRF and lower damping characteristics. Furthermore, the natural frequencies and mode shapes obtained by the proposed method was consistent with the single-shaker testing data obtained by the conventional method. Therefore, the proposed method primarily influences the damping characteristics of the vibration system as a target and facilitates the identification of modal parameters.