Determine critical damping of multimass system

tiljoachim

Hi

I have a spring mass damper system with multiple masses. Is there any way I can calculate the magnitude of the damping in order to get a critical damped system?

I have the scaling of the dampers(c1/c2) and they are connected in series.
c_eq=c1+c2...

I tried with the formula:

ζ=1=c_eq/(2*m_eq*ω_n)

ω_n=√(k/m)

But it doesnt give the correct results so I did a FFT of the response to find the most dominating frequency and put in this new omega but without succes. Is it possible at all to determine a damping that satisfies this if the scaling(c1/c2) is to large?