A machine rests on spring mounts, which compress by 15 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 8 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 15 kg mass is supported by a spring with a stiffness of 80 kN/m and a viscous damper with a damping coefficient of 440 N·s/m. Find the damping ratio ζ.
A 2 kg mass is supported by a spring with a stiffness of 8 kN/m and a viscous damper with a damping coefficient of 100 N·s/m. Find the damping ratio ζ.
A 10 kg mass hangs from two springs connected end to end (in series): the upper spring has k₁ = 100 kN/m and the lower one k₂ = 12 kN/m. Find the equivalent stiffness keq of the spring system in kN/m.
A 100 kg mass hangs from spring k₃ = 60 kN/m. The top of k₃ is attached to a rigid bar that hangs from two springs side by side, k₁ = 15 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 = 4.07 Hz
- 2. fn = 5.573 Hz
- 3. ζ = 0.2008
- 4. ζ = 0.3953
- 5. keq = 10.71 kN/m
- 6. fn = 2.172 Hz
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