A mass of 5 kg is suspended from a spring of stiffness 46 kN/m. A dashpot is fitted between the mass and the support with a damping ratio of 0.3. Calculate the damped frequency.
The natural undamped
frequency is given by
fn=12π√kM⇒fn=12π√460005=15.26Hz
The damped frequency is given by
f=fn√1−δ2=15.26×√1−0.09=14.56Hz