Robert Pascarella

An Analysis of Yaw Inducing Drag Forces Imparted During Tire Tread Belt Detachments

In this study, tests were performed to understand the effects of asymmetric longitudinal forces on vehicle response which may be created in certain staged partial tire tread belt detachment tests. In a very small number of tests performed by others, tires cut to simulate partial tire tread belt detachments created longitudinal drag forces at the separating tire that induced substantial vehicle yaw. This drag force and yaw response are independent of vehicle type and suspension type; they are created by the separating tire tread interacting with the road surface and/or vehicle. Similar yaw inducing drag forces are further demonstrated by applying braking to only the right rear wheel location of an instrumented test vehicle. It is shown that vehicle yaw response results from this longitudinal force as opposed to vertical axle motion.

Steering and Handling Performance During a Full Tire Tread Belt Separation

In this study, tests were performed with modified tires at the various front and rear positions on seventeen different vehicles to determine the effect of a full tire tread belt separation on a vehicle at highway speeds. The drivers steering and braking inputs were measured along with the vehicle responses during the event. The results show that the forces of a full tread belt separation generally do not force a vehicle out of a drivers control and that only small steering corrections are required to remain in the original lane of travel during the tread belt separation event. Additionally, forces due to the separating tires do not result in violent hop or tramp suspension responses during the separation event. 2011 SAE International.