A Study of Lateral and Longitudinal Tire Forces Produced on a Deformable Surface with Applied Traction and Braking

Abstract

An investigation into the effects that changing tire characteristics have on the production of lateral and longitudinal tire forces was conducted on a test wheel that was subjected to external traction and braking forces. The test tire’s slip angle, camber, inflation pressure and normal load were adjusted as the test wheel was run over a prepared piece of deformable test terrain consisting of a fine particle, remolded clay. Force data was collected using a series of load cells and tire angular velocity was collected from a Hall Effect senor and encoder wheel. The data was analyzed and several conclusions were reached about the effects that the tire characteristics have on both lateral and longitudinal force production. Tire friction ellipses were also created using the collected data to provide a more complete picture of the tire’s performance during combined slip conditions i.e. a vehicle maneuvering with applied traction.