TRIBOLOGICAL SYSTEM OF TIRE WEAR

YIN-YU CHENMANE6960 – FRICTION WEAR AND LUBRICATION OF

MATERIALSPROFESSOR ERNESTO GUTIERREZ-MIRAVETE

MAY 13, 2015

Introduction

• Tire: A protective cover to contain compressed air in a toroidal chamber that is attached to a steel rim or wheel of an automobile– The tire must transmit forces from the car to the road during

driving– The tire must provide a firm grip on the road

• May be dry or wet• Sometimes contaminated — intentionally (salt during winter) or

accidentally (spillage)

– The tire is also used to absorb unevenness of the road and provide a comfortable journey

– Tire has to do this at a low cost and must have a sufficiently long life with ample safety provisions against accidental deflation

Wear Characteristics

• Tread loss– The averaged value of the depth loss of tread

through wear. It is measured for all the grooves and expressed in millimeters

• Rate of wear– Loss of tread (i.e. millimeters per 10,000 km of

travel)• Tread wear index– The ratio of wear rate of a control or reference tire

to that of the experimental tire, expressed in percent

Tire Wear SystemArchard Wear Theory

• V is the total volume of wear amount• K is the wear coefficient• FN is the normal load of the contact pair• H is the hardness of the tire• L is the slip distance• P is the normal pressure of contact surface• A is the contact area

Tire Wear SystemArchard Wear Theory

• is the slip ratio• t is the time• is the ratio of volume wear