A machine rests on spring mounts, which compress by 4 mm under its weight. Treat it as an undamped single-degree-of-freedom system and use g = 9.81 m/s². Find the natural frequency fn of vertical vibration in Hz.
Mechanical vibrations worksheet with answers
A machine rests on spring mounts, which compress by 20 mm under its weight. Treat it as an undamped single-degree-of-freedom system and use g = 9.81 m/s². Find the natural frequency fn of vertical vibration in Hz.
A 10 kg mass is supported by a spring with a stiffness of 50 kN/m and a viscous damper with a damping coefficient of 350 N·s/m. Find the damping ratio ζ.
A 25 kg mass is supported by a spring with a stiffness of 20 kN/m and a viscous damper with a damping coefficient of 570 N·s/m. Find the damping ratio ζ.
A 25 kg mass hangs from two springs side by side (in parallel), with stiffnesses k₁ = 15 kN/m and k₂ = 50 kN/m. The mass stays level. Ignore damping and the masses of the springs. Find the natural frequency fn of vertical vibration in Hz.
A 40 kg mass hangs from spring k₃ = 20 kN/m. The top of k₃ is attached to a rigid bar that hangs from two springs side by side, k₁ = 80 kN/m and k₂ = 12 kN/m; the bar stays level. Ignore damping and the masses of the springs and bar. Find the natural frequency fn of vertical vibration in Hz.
Answer key
- 1. fn = 7.882 Hz
- 2. fn = 3.525 Hz
- 3. ζ = 0.2475
- 4. ζ = 0.4031
- 5. fn = 8.115 Hz
- 6. fn = 3.225 Hz
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