Topic: Vibrations
Which of the following is TRUE for vibration of a mechanical system
- A. Damping ratio is the ratio of the critical damping to the actual damping
- B. The damping can be obtained using logarithmic decrement method
- C. For damped systems, amplitude becomes infinity at resonance
- D. Amplitude ratio is unity when the exciting force frequency is √2 times the natural frequency
Answer: D. Amplitude ratio is unity when the exciting force frequency is √2 times the natural frequency
Explanation: (d) is correct. For a transmissibility calculation, when the frequency ratio (ω/ωn) is √2, the transmissibility T.R. becomes 1, regardless of the damping ratio.