Figure 1. A320 Takeoff
I recently flew as a passenger in an A320 similar to the aircraft shown in Figure 1.
Figure 2. Time History Plots
The takeoff vibration is shown in Figure 2 for the lateral and vertical axes. The aircraft went airborne at 393 seconds. The fore-aft axis is omitted since its level was lower. The sensor was a Slam Stick X mounted on the cabin floor.
Figure 3. PSD, Lateral Axis
Figure 4. PSD, Vertical Axis
The PSD plots show some distinct spectral peaks which are most likely forcing frequencies, or possibly lightly-damped structural resonances.
Here is the time history data file: takeoff_data
– Tom Irvine