TRUCK TIRE VIBRATION SOUND

Tire sound and vibration signals were recorded simultaneously to obtain a record of both the vibration source and the resulting sound field. Vibration normal to the tire surface was measured in the tread region by miniature piezoelectric accelerometers. The sound was monitored by a one-inch condensor microphone placed close behind the tire. A synchronizing pulse from a photoelectric pickoff furnished a once-per-rotation marker for orienting accelerometers relative to the road surface. This paper discusses analyses of the test data to determine sound radiation mechanisms. It covers characterization of tire vibration time histories, decay of vibration amplitude, effects of damping and wavespeed, and computation of sound pressure.