The desired vibration level for helicopters is 005 g for the

The desired vibration level for helicopters is 0.05 g for the cabin for all flight conditions. If the helicopter primary forcing function is 20 Hz, What would be the amplitude of vibration?

Solution

Given

acceleration a = 0.05g m/s²

= 0.05 X 9.81

= 0.4905

Frequency of forcing function, f = 20 Hz

Hence angular velocity, omega = 2 X pi X f

= 2 X 3.14 X 20

= 125.66 rad/s

Amplitude of vibration, y = a / omega²

= 0.4905 / (125.66)²

= 3.11 X 10^-5 m

= 0.031 mm