Effect of fast parametric viscous damping excitation on vibration isolation in sdof systems

In this work, we investigate analytically the effect of cubic nonlinear parametric viscous damping on vibration isolation in sdof systems. Attention is focused on the case of a fast parametric damping excitation. The method of direct partition of motion is used to derive the slow dynamic and steady-state solutions of this slow dynamic are analyzed to study the influence of the fast nonlinear parametric damping on the vibration isolation. This study shows that adding periodic nonlinear damping variation to the vibration isolation device can reduce transmissibility over the whole frequency range. The results also reveals that this nonlinear parametric viscous damping enhances vibration isolation comparing to the case where the cubic nonlinear damping is time-independent.