Correlation between Ultrasonic Nondestructive Inspection and Wheel Test of 34 Retreaded Tires

摘要

The report covers a test in which 34 retread tires were inspected using reflection ultrasound nondestructive inspection, wheel tested and then subjected to failure analysis by sectioning. The results demonstrate for the first time the ability of ultrasound to identify and classify defects in tires which lead to failures. The nondestructive inspection (NDI) carried out on all 34 tires identified five tires which had major flaws, predominantly separations, and five tires with minor flaws. The wheel test was an 8-hour full-load 55 MPH test in which 6 of the 34 tires failed. All 6 failed tires were analyzed by an outside contractor and the results compared with flaw assessments made by nondestructive inspection. All 6 failed tires came from the ten identified by NDI as having flaws. Five of the six were tires listed as having major flaws by NDI with agreement between non-destructive inspection and failure analysis. Recommendations arising from the study are that the work be used more extensively to support NHTSA's ongoing rule enforcement activities; particularly in the area of identifying and defining separations as cited in FMVSS 109 and buff damage as cited in FMVSS 117.