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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
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Tire-pavement noise modelingTire-pavement noise modeling
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freq
SPL
freq
SPL
Predicted Measured
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freq
SPL
freq
SPL
Pavement parameters
Tire parameters
Atmospheric conditions
Vehicle conditions
Predicted Measured
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Vibration model
Noise measurement
Noise prediction
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The problemThe problem
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Vibration model
Noise measurement
Noise prediction
Background noise
Air pumping noise
Propagation effects
Sound absorption
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Vibration model
Noise measurement
Noise prediction
Background noise
Air pumping noise
Propagation effects
Sound absorption
Vibration measurement
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Vibration measurementVibration measurement
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Laser Doppler vibrometryLaser Doppler vibrometry
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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
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Embedded accelerometerEmbedded accelerometer
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Embedded accelerometerEmbedded accelerometer
ta
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Embedded accelerometerEmbedded accelerometer
AdvantagesAdvantages DisadvantagesDisadvantages
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
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Can the disadvantages of Can the disadvantages of accelerometer methods be accelerometer methods be
overcome?overcome?
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Embedded accelerometerEmbedded accelerometer
AdvantagesAdvantages DisadvantagesDisadvantages
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
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Embedded accelerometerEmbedded accelerometer
DisadvantagesDisadvantages
Mass-loading effectMass-loading effect
Results difficult Results difficult to interpretto interpret
Modification of tireModification of tire
0.2 grams0.2 grams
ta
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On-board sound intensity probeOn-board sound intensity probe
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Triggering systemTriggering system
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t
acce
lera
tion
twhe
eltr
igge
r
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t
twhe
eltr
igge
rac
cele
ratio
n
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t
t
t
pave
men
ttr
igge
rw
heel
trig
ger
acce
lera
tion
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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
)
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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
)
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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
)
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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
)
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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
)
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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
)
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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
)
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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
)
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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
)
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Leading edge
Trailing edge
Entrance of contact patch
Exit of contact patch
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ApplicationApplication
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Wheel-slap noiseWheel-slap noise
Contraction jointsContraction joints
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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?
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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
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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
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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
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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
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-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)
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-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)
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-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)
A0 = 76.0, = 0.0181
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-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)5.4 m/s
-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)
8.0 m/s
-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)
10.7 m/s
-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)
13.4 m/s
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-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)5.4 m/s
-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)
8.0 m/s
-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)
10.7 m/s
-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)
13.4 m/s
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-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)
A0 = 23.7
= 0.0181R2 = 0.86
5.4 m/s
-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)
A0 = 45.1
= 0.0181R2 = 0.93
8.0 m/s
-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)
A0 = 64.5
= 0.0181R2 = 0.90
10.7 m/s
-120 -90 -60 -30 00
50
100
angle from contact patch, (degrees)
impu
lse st
reng
th (g
)A
0 = 76.0
= 0.0181R2 = 0.91
13.4 m/s
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6 7 8 9 10 11 1212
13
14
15
16
17
18
19
20
speed level, Ls (dB re: 1 m/s)
impu
lse st
reng
th le
vel,
L A (dB
re: 1
g)
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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
speed level, Ls (dB re: 1 m/s)
impu
lse st
reng
th le
vel,
L A (dB
re: 1
g)
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Noise: Πjoint ∝ s4
Flexural wave: A0 ∝ s1.3
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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)
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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
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inefficient radiator
Wave speed = 66 m/s
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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
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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
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Thank youThank you