\[fig:Cycle2\]) which contrasts with the first example where the damping ratio was quite small.

The modal quantities are represented in figures \[fig:ModesNL2\].

There are several differences in this example with reference to the previous one. First note that there is no instability region and no internal resonance. Then the modal damping curve is quite different from the previous example since the dashed line branch reach higher values of damping especially in the region where the two frequency curves could interact. In effect, figure \[fig:Cycle2\] shows a particular feature of this nonlinearity which is that the level of nonlinearity (in this case, the drop of stiffness) is directly related to the level of damping. As a consequence, a too high value of nonlinear damping can inhibit the resonance capture and no energy pumping occurs and two oscillators behave quite independently.

This comparison clearly shows this importance of the level of dissipation in the nonlinearity on the efficiency of the energy pumping phenomenon. However, remember that, in the energy pumping phenomenon, as the vibratory energy gets transferred to the absorber it has to be dissipated. The optimal absorber would then be the one with the highest damping ratio allowing the resonance capture 