Tuning and Optimal Performance of an Asymmetric Vibro-Impact Nonlinear Energy Sink with Dry Friction

This paper presents a design-oriented framework for asymmetric vibro-impact nonlinear energy sinks (VI-NES) with dry friction. In this context, asymmetry arises from directional differences in friction and restitution properties. The proposed approach builds on analytical results from the Multiple Scales Method (MSM) and an impact map formulation developed to fully characterize near-resonant dynamics in symmetric frictional configurations. The absence of closed-form solutions for asymmetric systems motivates a pragmatic design hypothesis that bounds their response using symmetric reference systems. Based on this insight, a performance-driven design strategy is established, enabling efficient evaluation and optimization without exhaustive simulations. The cavity length, identified as the dominant tuning parameter, governs activation, dissipation efficiency, and regime transitions. Analytical, numerical, and experimental results confirm the predicted tunability of the asymmetric VI-NES through geometric adjustment and demonstrate the robustness and applicability of the proposed strategy for passive vibration mitigation in realistic mechanical systems.