Predicting Residual Casing Life of a Tire following an Impact Event

By applying recognized engineering methods, including finite element analysis, the role of impact events on the service life of a tire was studied by varying three factors: speed of impact, treadwear, and angle of impact. The approach combines well-known finite element analysis methods to simulate a tire rolling over an obstacle with the calculation of damage at the tire belt edge imparted by the impact event by using recognized methods of rubber fatigue analysis. An efficient method is developed and used to demonstrate that across a range of impact conditions, some conditions can cause substantial internal damage, whereas other conditions can cause very little damage. The area of investigation is the tire belt edge; thus, although significant internal damage may have occurred, it might not be visually perceptible in the normal operation of a vehicle. In some cases, the nondetectable damage is shown to propagate to a point where the tire loses its structural integrity before reaching its normal operating life defined by treadwear. This study includes the role of mechanical, temperature, and rate effects.