Question

An accelerometer has a damping ratio of 0.5 and a natural frequency of 18,000 Hz. It is used to sense the relative displacement of a beam to which it is attached. (a)If an impact to the beam imparts a vibration at 4500 Hz, calculate the dynamic error and phase shift in the accelerometer output. (b)Calculateits resonance frequency.(c)What isthe maximumpossiblemagnitude ratio that the system can achieve

Answer 1

Answer:

A) i) Dynamic error ≈ 3.1%

   ii) phase shift ≈ -12°

B) 79971.89 rad/s

Explanation:

Given data :

Damping ratio = 0.5

natural frequency = 18,000 Hz

a) Calculate the dynamic error and phase shift in accelerometer output at an impart vibration of 4500 Hz

i) Dynamic error

This can be calculated using magnitude ratio formula attached below is the solution

dynamic error ≈ 3.1%

ii)  phase shift

This phase shift can be calculated using frequency dependent phase shift formula

phase shift ≈ -12°

B) Determine resonance frequency

  Wr = 2$\pi$ ( 18000 $\sqrt{0.5}$ ) = 79971.89 rad/s

C) The maximum magnitude ratio that the system can achieve