The problem with damping

To myself,

The code from the Deolasi formulation is now yielding some results. However the accuracy is doubtful. I have a fair idea that Udar's results might be erroneous. At best, I was able to match only sections. This is especially true if a second order method is used. While dealing with combination resonance frequencies of higher modes, the onset and width of the first-order method correspond to what's reported by Udar and Datta.

Also, the values match when the damping parameter, $\zeta=0.005$, instead of $\zeta=0.05$.

Need to have a talk with my guide.

Regards.