Broadband Interband Targeted Energy Transfer in Multi-Resonators Metamaterials with Vibro-Impact Nonlinearity

The capability of metamaterials to achieve irreversible interband targeted energy transfer (IBTET) between frequency bands, as well as within the initially excited band, is crucial for developing elastoacoustic devices, like diodes and logic gates. Although recent studies show that nonlinear lattices can exhibit IBTET, existing mechanisms operate over a limited excitation range. This work aims to overcome these limitations using one-dimensional (1D) metamaterials with multiple local resonators (LRs) subjected to vibro-impact (VI) nonlinearity. In the presence of multiple LRs, multiple optical bands are formed. Consequently, excitation within a selected optical band can activate the VI nonlinearity, enabling energy scattering over a wider range of excitation frequencies. We perform numerical simulations on a semi-infinite 1D lattice with free boundaries, considering different spatial distributions of VI elements and multiple input energy levels. The results show that the proposed lattice exhibits robust IBTET at intermediate energy levels. Unlike mechanisms reported in the literature, the proposed system can be activated from multiple optical bands, indicating operation across a broader frequency range. Notably, the system enables energy transfer not only from high to low frequency bands and vice versa, but also within the excited band. Using a wavelet-based modal decomposition technique, the redistributed energy is decomposed into different frequency bands and within the excited band itself to quantify the amount of energy scattered. Finally, a parametric study is conducted to assess the influence of some key system parameters on scattered energy, providing guidance for tuning the design toward optimized elastoacoustic devices.