Guangming Wang, Ph.D., P.E.

Dennis Morian, P.E.; Doug Frith, P.E.

Quality Engineering Solutions, Inc

Effects of Tire Axle Load and Inflation Pressure on

Near-Surface Pavement Response

Outline

• Background

• Develop 2-D Axle-Tire-Pavement Contact

Model

• Investigate Tire Axle Load and Inflation

Pressure on Near-Surface Pavement

Response

• Conclusions & Recommendation

Background

• Damaging Effects of Overloaded/Heavy Loaded Vehicles to Pavements

Background (Cont.)

• Pavement damage follows approximately a 4th-power rule, which means that if the load is doubled, the damage will be 16 (2^4). • If the load is increased by 20%, the damage is doubled!

Background (Cont.)

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 2 4 6 8 10 12 14 16 18 20

Age of Pavment (Year)

Pavem

en

t S

erv

ice In

dex

Standard Design Heavy Trucks Start at Year 0 Heavy Trucks Start at Year 10

Heavy/Over Load results in fewer allowable repetitions before failure

(Source: Wilde, 2012)

Background (Cont.)

• Damaging Effects of Under/Over Inflated Tires to Pavements

Background (Cont.)

• Top-down Cracking and Instability Rutting

Develop 2-D Axle-Tire-pavement Model

• Tire to Be Modeled

Michelin X One® XDA-HT™ Plus 445/50R22.5

Develop 2-D Axle-Tire-Pavement Model (Cont.)

• Modeling of Tire

Develop 2-D Axle-Tire-Pavement Model (Cont.)

0

20

40

60

80

100

120

140

160

0 2 4 6 8 10

Tire Ribs

Ma

xim

um

Ve

rtic

al

Co

nta

ct

Str

es

s (

ps

i)

Predicted

Measured

-160

-140

-120

-100

-80

-60

-40

-20

0

20

40

-10 -5 0 5 10

Tire Lateral Distance (in)

Ve

rtic

al

Co

nta

ct

Str

es

s (

ps

i)

-50

-40

-30

-20

-10

0

10

20

30

40

50

-10 -5 0 5 10

Tire Lateral Distance (in)

La

tera

l C

on

tac

t S

tre

ss

(p

si)

• Model Verification

Develop 2-D Axle-Tire-Pavement Model (Cont.)

Effects of Axle Load on Near-Surface

Pavement Response

-200

-150

-100

-50

0

50

-10 -5 0 5 10

Tire Lateral Distance (in)

Vert

ical C

on

tact

Str

ess (

psi)

13.5k lbs 18k lbs 22.5k lbs

Effects of Axle Load on

Near-Surface Pavement Response (Cont.)

-60

-40

-20

0

20

40

60

-10 -5 0 5 10

Tire Lateral Distance (in)

Tra

nsvers

e C

on

tact

Str

ess (

psi)

13.5k lbs 18k lbs 22.5k lbs

Effects of Axle Load on

Near-Surface Pavement Response (Cont.)

0

20

40

60

80

100

13.5k 18k 22.5k

Axle Load (lbs)

Str

es

s (

ps

i)

Max. Shear Stress Principle Tensile Stress

Effects of Tire Inflation Pressure

on Near-Surface Pavement Response

Over Inflation Under Inflation Correct Inflation

-200

-150

-100

-50

0

50

-10 -5 0 5 10

Tire Lateral Distance (in)

Ve

rtic

al C

on

tac

t S

tre

ss

(p

si)

80 psi 100 psi 125 psi

Effects of Tire Inflation Pressure

on Near-Surface Pavement Response (Cont.)

-60

-40

-20

0

20

40

60

-10 -5 0 5 10

Tire Lateral Distance (in)

Tra

ns

ve

rse

Co

nta

ct

Str

es

s (

ps

i)

80 psi 100 psi 125 psi

Effects of Tire Inflation Pressure

on Near-Surface Pavement Response (Cont.)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

50 55 60 65 70 75 80

Maximum Shear Stress (psi)

De

pth

to

AC

Su

rfa

ce

(in

)

80 psi

100 psi

125 psi

Effects of Tire Inflation Pressure

on Near-Surface Pavement Response (Cont.)

0

5

10

15

20

25

80 100 125

Tire Inflation Pressure (psi)

Peak S

IGM

A-1

(p

si)

Conclusions

• The developed 2-D axle-tire-pavement finite element contact model can successfully capture patterns of both vertical contact stress and horizontal shear contact stress distributions.

• The maximum contact stress moved from the tire center towards the tire edges when the tire was heavily loaded or under inflated.

Conclusions (Cont.)

• Both peak SIGMA-1 and maximum shear stress increase with the axle load. The peak SIGMA-1 and maximum shear stress slightly increase with the decrease of the inflation pressure, which indicates that under inflation might increase the propensity of top-down cracking and instability rutting.

Future Research Recommendation

• Need to develop 3-D tire-pavement

interaction model to further investigate

the effects of tire axle load and

inflation pressure on the near-surface

pavement response.

Reference

• Greg A. Hayes and Keith Williamson. Minnesota’s Truck Weight

Education Program. Presentation for Minnesota Assn. of

Townships.

• Wilde W. James. Effect of Heavy Loads on Pavements.

Presentation for Houston County Board of Commissioners

Meeting, March, 2012.

Thank You