Treading new ground

Mechanical engineers at Purdue University have developed a system that uses sensors and mathematical models to detect defects in newly manufactured tyres better than conventional inspections.

The diagnostic technique works by analyzing vibration waves passing through a tyre to detect damage that leads to cracks in the bead area, where the tyre connects to the steel rim of the wheel. A crack will sometimes form in the bead area and spread entirely around the tyre, causing the tyre to lose air or otherwise fail, said Douglas E. Adams, an associate professor of mechanical engineering who developed the system with doctoral student Timothy J. Johnson.

The US National Highway Traffic Safety Administration issued the new tyre-durability standards covering aspects including the detection of bead-area damage after Congress in 2000 passed the TREAD Act, for Transportation Recall Enhancement, Accountability and Documentation. The law was prompted by a series of SUV accidents in the 1990s, some fatal, which resulted in the recall of 6.5 million tyres.