Passive energy redirection in a phononic lattice network through nonlinear wave scattering mechanisms

This work investigates passive energy redirection in a network of coupled phononic lattices enabled by nonlinear scattering mechanisms that arise from the synergy of geometric and vibro-impact nonlinearities in optimized internal resonators. Unlike linear lattices, where wave propagation is governed solely by dispersion relations, the incorporation of localized nonlinear features facilitates amplitude and frequency dependent energy transfers in a priori selected pathways. In particular, we show how energy induced by incoming wave packets with varying central frequencies is preferentially redirected into a selected pathway (lattice) solely based on its frequency content. This enables frequency-selective passive routing without the need for active control. Wavelet-based signal processing, integrated with an energy management methodology, is employed to quantify and interpret the redistribution of wave energy across the time–frequency domain. To address the optimization of directed energy transfer in the high-dimensional design space of this phononic system, we employ a multi-objective genetic algorithm (MOGA) to optimize key system parameters. This yields Pareto-optimal solutions that capture the trade-offs between competing redirection objectives. This study confirms the effectiveness of nonlinear scattering through the synergy of internal resonance, vibro-impacts, and geometric nonlinearities in enabling robust and efficient passive energy control. These results point toward new opportunities for vibration mitigation, energy harvesting, targeted energy transfer, and effective wave manipulation in phononic and acoustic metamaterials.