Transcript RESS-4-19 vibration-test for RESS 1. quantification the load of different vibration profiles with a test specimen 2.

RESS-4-19
vibration-test for RESS
1. quantification the load of different vibration profiles
with a test specimen
2. proposal for a test-profil
evaluated profils for vibration test
•
vibration signal of a car on proving
ground (example)
•
random vibration ISO12405 vertical
•
8g-Sweep UN38.3
•
2g-Sweep proposal
strain gage
test specimen
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load direction
sweep-signal
The vibration shall be a sinusoidal waveform with a logarithmic sweep between 7
Hz and 200 Hz and back to 7 Hz traversed in 15 minutes. This cycle shall be
repeated 12 times for a total of 3 hours for each of three mutually perpendicular
mounting positions of the RESS.
UN38.3 8g-sweep
from 7 Hz to a peak acceleration of 1 gn is maintained until 18 Hz is reached. The
amplitude is then maintained at 0.8 mm (1.6 mm total excursion) and the frequency
increased until a peak acceleration of 8 gn occurs (approximately 50 Hz). A peak
acceleration of 8 gn is then maintained until the frequency is increased to 200 Hz.
Proposal 2g-sweep
from 7 Hz to a peak acceleration of 1 gn is maintained until 18 Hz is reached. The
amplitude is then maintained at 0.8 mm (1.6 mm total excursion) and the frequency
increased until a peak acceleration of 2 gn occurs (approximately 25 Hz). A peak
acceleration of 2 gn is then maintained until the frequency is increased to 200 Hz.
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from proving-ground (example)
power spectral density (PSD) vibrationsignal
random vibration ISO12405 vertical
8g-sweep UN38.3
of test-profils
2g-sweep proposal
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load of test speciment
vibrationsignal from proving-ground (example)
random vibration ISO12405 vertical
8g-sweep UN38.3
maximalwerte
2g-sweep proposal
max. strain on test
specimen
1
0,8
max. strain [mV/V]
absoluter Maximalwert [mV/V]
0,6
0,4
0,2
0
-0,2
-0,4
-0,6
-0,8
-1
Messstellepoint
15 Hz 15Hz
measuring
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Messstelle
30 Hz30Hz
measuring
point
Messstelle
75 Hz
measuring
point
75Hz
load of test speciment
vibrationsignal from proving-ground (example)
random vibration ISO12405 vertical
8g-sweep UN38.3
2g-sweep proposal
fatigue damage on test specimen,
relative to vibrationsignal from proving-ground
1.000.000
100.000
auf Zielprüfdauer extrapoliert
extrapolated
to target
damage
relative fatigue
rel. Belastungskennzahl
10.000
1.000
100
10
1
0
Messstelle
Hz
measuring
point15
15Hz
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Messstelle
Hz
measuring
point3030Hz
Messstelle
75 75Hz
Hz
measuring
point
measured accelerations,
power spectral density
range of measured accelerations
(vertical) on car body, approx. 50 different
cars
0,1
[g²/Hz][g²/Hz]
PSDLesitungsdichte
0,01
•
micro compact car
•
luxury sedan
•
roadster
•
SUV
•
…
0,001
0,0001
0,00001
1
10
Frequenz [Hz]
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100
measured accelerations
frequency spectrum FFT
Fahrersitzkonsole vorn links Z-Richtung
Fahrersitzkonsole vorn links Z-Richtung
2
Beschleunigung [m/s²]
2
car body - frequency spectrum
accelerationy [g]
1.5
micro compact car
1
0.5
1
0
20
40
60
80
100
120
140
160
180
200
0
frequency
[Hz]
Frequenz [Hz]
Integralträger vorn links Z-Richtung
2
5
10
15
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25
30
frequency
Frequenz[Hz]
[Hz]
2
-Spyder10_20101129_166_V01_StuPeakMax_por_90 (1.Kurve)
1
20
Integralträger vorn links Z-Richtung
•no significant response upwards 50 Hz
1.5 compact car
•highest peaks for micro
1.5
0.5
0
1
0.5
r-Spyder10_20101129_166_V01_StuPeakMax_por_90 (1.Kurve)
0
micro compact car
0.5
Beschleunigung [m/s²]
accelerationy [g]
1.5
car body - frequency spectrum
RESS vibration test proposal
frequency acceleration acceleration
[g]
[Hz]
[m/s2]
5 - 18
1
10
18 - 30
0,5
5
30 – 50
0,2
2
12
acceleration [m/s^2]
11
10
9
8
7
6
5
4
3
2
acceleration – frequency curve
1
0
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
frequency [Hz]
• maximum acceleration 10m/s^2 (1g), maximum frequency 50 Hz
• sinusoidal waveform with a logarithmic sweep
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RESS vibration test proposal
At the request of the manufacturer, a higher acceleration level as well as a higher
maximum frequency can be conducted. In the case of a higher maximum
frequency, the lowest frequency can be greater than 5 Hz, but shall not exceed
10% of the highest frequency.
At the request of the manufacturer a test profile determined by the vehiclemanufacturer, verified to the vehicle application and agreed by the Technical
Service can be used as a substitute of the frequency – acceleration correlation
of the proposal.
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