NASHVILLE, Tenn (Oct. 17, 2000) — The independent expert hired by Bridgestone/Firestone Inc. to investigate possible problems with its Firestone P-metric light truck tires is focusing on the fatigue properties of the rubber layer between the tire´s steel belts.
"All evidence to date points to a slowly developing fatigue crack that propagates through the belt wedge material and then subsequently into the belt skim between the steel belts," wrote Sanjay Govindjee, the University of California-Berkeley associate professor of civil engineering brought in to conduct an independent investigation, in a letter to Bridgestone/Firestone.
"At some stage, the cracks reach a critical size and the tires subsequently fail," he said.
Mr. Govindjee also wrote that the problem is a "quite complex interaction of the effects of tire design, the manufacturability of the tire, and loading conditions. He expects to have a preliminary technical report done by the end of October and a final report early in 2001.