Page 43 - Shock and Vibration Overview
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Analysis Overview
Figure 25: Random vibration levels on the seat of a commercial airliner.
There is definitely a resonance of that seat around 250 Hz; but there is surprisingly
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steady broadband vibration of 10 g /Hz from 1 Hz to 1 kHz. This PSD could be used to
program an exposure profile in a laboratory shaker to allow an engineer to do some in-
house testing ahead of a field test. Because this was from actual data in the actual
environment, the engineers have confidence that their system can survive. It’s
incredibly valuable to go out and actually measure the environment than to simply rely
on some test standard. These test standards will recommend using the standard’s data
as a guide; but they typically try and encourage the engineer to go out and get the
actual vibration data. Nothing beats the real data!
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