System for Non-Destructive Testing of Tire Sidewalls

摘要

Tire inspection has previously used x ray, shearography, and low resolutionultrasound to inspect portions of a tire but not the entire tire Dow97. Recently Reis demonstrated acousto-ultrasonic inspection to detect belt damage in steel-belted radial tire sidewalls Rei97. Each technique is noted for its ability to detect certain types of problems within the rubber composite material of the tire in specific locations without providing a scan of the entire tire. Ultrasound in particular has been shown to be capable of detecting disbond and material property changes within the material Rog92. Specifically, the acoustic impedance of the material is altered in locations with disbond and/or material property changes. The change in acoustic impedance can be used to detect tire flaws using high resolution 2-D scanning to locate areas with acoustic impedance changes. Material property changes are often associated with heat damage to the material. Heat can cause additional crosslinking between long-chain molecules within material and change the acoustic properties. Heat can also cause a reduction in crosslinking known as reversion that also changes the acoustic properties of the material Fre89. Disbond affects the acoustic impedance of the material by reflecting a part of the ultrasound beam. Recent advances in data-acquisition and control technology have allowed large data-set, high speed inspection systems to be produced. The use of inexpensive PC (Personal Computer) based data