Towards a bistable vibroacoustic nonlinear absorber: optimum efficiency of a bistable nonlinear energy sink

Previous works have demonstrated that an elastic membrane can be coupled to an acoustic system and act as a nonlinear energy sink (NES). In this work we study a new design of a bistable vibroacoustic nonlinear absorber. We use NES membranes and change the characteristics of the membranes from monostable to bistable by changing their linear stiffness. We evaluate the efficiency of the bistable membrane using a numerical approach that allows us to compare the attenuation efficiency of the bistable and monostable NES membranes, and find the optimum stiffness. Then we validate it experimentally. We also present analytical tools and we use them to explain the behavior of the membrane and the specific effects of the bistability property. The numerical approach is applied to different membrane configurations with the same results: bistability can improve the efficiency of a vibroacoustic nonlinear absorber.