Accelerometer measurements of tire carcass vibrations and implications to tire-pavement noise

Accelerometer measurements of tire Accelerometer measurements of tire carcass vibrations and implications to carcass vibrations and implications to tire-pavement noisetire-pavement noise

Tyler DarePurdue University

Robert BernhardUniversity of Notre Dame

Tire-pavement noise modelingTire-pavement noise modeling

freq

SPL

freq

SPL

Predicted Measured

freq

SPL

freq

SPL

Pavement parameters

Tire parameters

Atmospheric conditions

Vehicle conditions

Predicted Measured

Vibration model

Noise measurement

Noise prediction

The problemThe problem

Vibration model

Noise measurement

Noise prediction

Background noise

Air pumping noise

Propagation effects

Sound absorption

Vibration model

Noise measurement

Noise prediction

Background noise

Air pumping noise

Propagation effects

Sound absorption

Vibration measurement

Vibration measurementVibration measurement

Laser Doppler vibrometryLaser Doppler vibrometry

Laser Doppler vibrometryLaser Doppler vibrometry

AdvantagesAdvantages DisadvantagesDisadvantages

Non-contactNon-contact

Single spatial pointSingle spatial point

No field No field measurementsmeasurements

No data from No data from contact patchcontact patch

Embedded accelerometerEmbedded accelerometer


ta



Data in contact patchData in contact patch

Field surfaces can Field surfaces can be measuredbe measured

Mass-loading effectMass-loading effect

Results difficult Results difficult to interpretto interpret

Modification of tireModification of tire

Can the disadvantages of Can the disadvantages of accelerometer methods be accelerometer methods be

overcome?overcome?



Data in contact patchData in contact patch

Field surfaces can Field surfaces can be measuredbe measured





DisadvantagesDisadvantages




0.2 grams0.2 grams

ta

On-board sound intensity probeOn-board sound intensity probe

Triggering systemTriggering system

t

acce

lera

tion

twhe

eltr

igge

r

t

twhe

eltr

igge

rac

cele

ratio

n

t

t

t

pave

men

ttr

igge

rw

heel

trig

ger

acce

lera

tion

05

1015

2025

30

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

-100

0

100

time (ms)

angle (degrees)

acce

l. (g

)

05

1015

2025

30

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

-100

0

100

time (ms)

angle (degrees)

acce

l. (g

)

05

1015

2025

30

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

-100

0

100

time (ms)

angle (degrees)

acce

l. (g

)

05

1015

2025

30

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

-100

0

100

time (ms)

angle (degrees)

acce

l. (g

)

05

1015

2025

30

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

-100

0

100

time (ms)

angle (degrees)

acce

l. (g

)

05

1015

2025

30

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

-100

0

100

time (ms)

angle (degrees)

acce

l. (g

)

05

1015

2025

30

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

-100

0

100

time (ms)

angle (degrees)

acce

l. (g

)

05

1015

2025

30

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

-100

0

100

time (ms)

angle (degrees)

acce

l. (g

)

05

1015

2025

30

-180

-150

-120

-90

-60

-30

0

30

60

90

120

150

180

-100

0

100

time (ms)

angle (degrees)

acce

l. (g

)

Leading edge

Trailing edge

Entrance of contact patch

Exit of contact patch

ApplicationApplication

Wheel-slap noiseWheel-slap noise

Contraction jointsContraction joints

Wheel-slap noiseWheel-slap noise

0 5 10 15 20 25 30 35 40 45 50-4

-2

0

2

4

time (ms)

A-w

eigh

ed s

ound

pre

ssur

e (P

a)

What causes the noise?What causes the noise?

250 315 400 500 630 800 1000 1250 1600 2000 2500 3200 4000 500055

60

65

70

75

80

85

frequency (Hz)

A-w

eigh

ted

OBS

I lev

el(d

B re

: 1 p

W/m

2 )

PCCPCC with joint

Speed coefficientsSpeed coefficientsΠ∝ sn

Sound powerSound power Vehicle speedVehicle speed

Speed Speed coefficientcoefficient

n = 0n = 0 ResonanceResonancen = 2–3n = 2–3 Tread block vibrationsTread block vibrationsn = 4–5n = 4–5 Air pumpingAir pumping

LLnoise noise = nL= nLss

6 7 8 9 10 11 1280

85

90

95

100

105

110

115

120

speed level, Ls (dB re: 1 m/s)

A-w

eigh

ted

OBS

I lev

el(d

B re

: 1 p

W/m

2 )

LOBSI

= 4.11 LS + 63.5 dB

R2 = 0.95

800 Hz one-third octave band wheel-slap noise

6 7 8 9 10 11 1280

85

90

95

100

105

110

115

120


A-w

eigh

ted

OBS

I lev

el(d

B re

: 1 p

W/m

2 )

LOBSI

= 4.11 LS + 63.5 dB

R2 = 0.95

800 Hz one-third octave band wheel-slap noise

Πjoint ∝ s4

-120 -90 -60 -30 00

20

40

60

80

100

angle from contact patch, (degrees)

impu

lse st

reng

th (g

)

A = A0 e

A0 = A

0(s)

-120 -90 -60 -30 00

20

40

60

80

100


impu

lse st

reng

th (g

)

A = A0 e

A0 = A

0(s)

-120 -90 -60 -30 00

20

40

60

80

100


impu

lse st

reng

th (g

)

A = A0 e

A0 = A

0(s)

A0 = 76.0, = 0.0181

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)5.4 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)

8.0 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)

10.7 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)

13.4 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)5.4 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)

8.0 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)

10.7 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)

13.4 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)

A0 = 23.7

= 0.0181R2 = 0.86

5.4 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)

A0 = 45.1

= 0.0181R2 = 0.93

8.0 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)

A0 = 64.5

= 0.0181R2 = 0.90

10.7 m/s

-120 -90 -60 -30 00

50

100


impu

lse st

reng

th (g

)A

0 = 76.0

= 0.0181R2 = 0.91

13.4 m/s

6 7 8 9 10 11 1212

13

14

15

16

17

18

19

20


impu

lse st

reng

th le

vel,

L A (dB

re: 1

g)

6 7 8 9 10 11 1212

13

14

15

16

17

18

19

20

Ls = 1.33 L

I + 4.22 dB

R2 = 0.98


impu

lse st

reng

th le

vel,

L A (dB

re: 1

g)

Noise: Πjoint ∝ s4

Flexural wave: A0 ∝ s1.3

0 0.002 0.004 0.006 0.008 0.010 0.0120

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

time, t (s)

circ

umfe

renti

al d

istan

ce, x

(m)

0 0.002 0.004 0.006 0.008 0.010 0.0120

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

time, t (s)

circ

umfe

renti

al d

istan

ce, x

(m)

x = 65.6 t - 0.03 m

R2 = 1.00

inefficient radiator

Wave speed = 66 m/s

Flexural wave at joint is not a Flexural wave at joint is not a major cause of increased noisemajor cause of increased noise

Speed coefficient Wave speed

ConclusionsConclusions

Flexural waves generated at joint do not Flexural waves generated at joint do not cause wheel slap noisecause wheel slap noise

Accelerometer measurements can be Accelerometer measurements can be made with little tire modificationmade with little tire modification

Vibration characteristics across the Vibration characteristics across the circumference can be measured with a circumference can be measured with a single transducersingle transducer

Thank youThank you

Documents

Accelerometer measurements of tire carcass vibrations and implications to tire-pavement noise