Acousto-ultrasonic damage evaluation of steel-belted radial tires

To demonstrate the feasibility of using the acousto-ultrasonic approach to detect and evaluate the severity of ply cord damage in steel belted radial tires, a blind study representative of a scenario in a tire manufacturing plant or retreading facility was carried out. The blind study consisted of the nondestructive testing and evaluation of seven tires of different manufacturers and construction. The acousto-ultrasonic (AU) stress-wave-factor (SWF) approach successfully detected and evaluated all damage in the ply cords in the seven tires used in this blind study. Furthermore, the approach was capable of ranking the tires according to their overall severity of damage. The results of this study also indicate that the acousto-ultrasonic approach is production-oriented and capable of 100% inspection of tires, reducing the number of discarded tire casings, and the expenses incurred when damaged tire casings are recapped. Furthermore, the results clearly indicate that ply cord damage, that can induce the Zipper Mode of Failure, can be detected before servicing the tire in order to eliminate a hazard condition with potential loss of life.