A vibrating system consists of a mass of 200 kg, a spring of stiffness 80 N/mm and a damper with damping coefficient of 800 N-s/m. What will be the natural frequency of damped vibration?

Question

Question

This question was previously asked in

BHEL Engineer Trainee Mechanical 24 Aug 2023 Official Paper

Answer 1

Concept:

The damped natural frequency of a vibrating system is given by

, where is the natural frequency and is the damping ratio.

Given:

Mass, m = 200 kg

Spring stiffness, k = 80 N/mm = 80000 N/m

Damping coefficient, c = 800 Ns/m

Calculation:

Undamped natural frequency,

Damping ratio,

Damped natural frequency,

Damped frequency in Hz,

Now,