Transcript Tribological System of Tire Wear.pptx

TRIBOLOGICAL SYSTEM OF TIRE WEAR
YIN-YU CHEN
MANE6960 – FRICTION WEAR AND LUBRICATION OF
MATERIALS
PROFESSOR 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 System
Archard Wear Theory
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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 System
Archard Wear Theory
•
is the slip ratio
• t is the time
•
is the ratio of volume wear