GMC chevrolet camaro 2000 Service Manual page 91

0-80 Vibration Diagnosis and Correction General Information
Beating (Phasing)
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Two separate disturbances that are relatively close
together in frequency will lead to a condition
called beating,· or phasing. A beating vibration
condition will increase in intensity or amplitude in a
repetitive fashion as the vehicle travels at a steady
speed. This beating vibration can produce the familiar
droning noise heard in some vehicles.
10 Hz
8Hz
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Beating occurs when two vibrating forces are adding
to each other's amplitude. However, two vibrating
forces can also subtract from each other's amplitude.
The adding and subtracting of amplitudes in sirnilar
frequencies is called beating. In many cases,
eliminating either one of the disturbances can correct
the condition.
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