Issue link: https://read.dmtmag.com/i/34501
FATIGUE RELATED DAMAGE • With or without a rupture – zipper* • Any damage that will allow the casing to oxidize or the casing plies to weaken or break • Run-flat tires (mainly dual positions) • Impacts to steel (not filled or repaired) • Improper repair or improper repair procedures (premature failure of repair) EFFECT: Exposed Steel Cord CAUSE: Detachment of Repair Product EFFECT: Any Damage That Will Allow the Casing to Oxidize CAUSE: Moisture *ZIPPER A fatigue related damage, with or without a rupture, occurs in the sidewall flex area of steel radial light and medium truck tires when it is subjected to excessive flexing or heat. This zipper rupture is a spontaneous burst of compressed air and the resulting rupture can range in length anywhere from 12 inches to 3 feet circumferentially around the tire. This is caused by the damage and weakening of the radial steel cables as a result of underinflation and the tire running flat. Eventually, the air pressure becomes too great for the cables to hold, and the area ruptures with tremendous force. EFFECT: Zipper Rupture CAUSE: Damage/Weakening of Radial Steel Cables as a Result of Underinflation and Running the Tire Flat MRT X-Ray Image of Fatigue-Related Damage Without a Rupture 108 Section Eight: Tire Damage