New Roughness Index of Passenger Car Rotational Vibration

Current road roughness indexes are limited to reflecting the unwanted rotational vibration of vehicles. This study focused on the relationship between the international roughness index (IRI) and rotational vibration around the longitudinal axis (pitch) and horizontal axis (roll) of the vehicle body. Sinusoidal wave input of different wavelengths and phase shifts between the left and right wheel tracks were used as excitation of a full-car model. Marked pitch and roll vehicle vibration were observed at shorter wavelengths (