Monday  |  Salon 12  |  04:00 PM–04:20 PM

#18409–Interband Targeted Energy Transfer and Wave Arrest in Strongly Nonlinear Lattices

Intentionally introducing nonlinearity into metamaterials has facilitated the development of novel elastoacoustic devices passively (e.g., diodes and waveguides). The performance of these devices is primarily governed by metamaterials' capability to achieve intermodal targeted energy transfer. In this study, we explore nonlinear locally resonant phononic metamaterials capable of significant interband targeted energy transfer (IBTET), that is, of nonlinear energy scattering from a dominant pass band to higher- or lower-frequency bands. The nonlinearity arises from pronounced geometric effects, specifically from the inclusion of inclined linear stiffness within the local resonator. This geometric modification can exhibit characteristics such as softening-hardening nonlinearity and bistability, contingent upon the initial angle of inclination. We conducted numerical simulations on a semi-infinite phononic lattice with varied distributions of nonlinearity and different initial angles of inclination of the internal resonators. The results demonstrate that the system exhibits robust IBTET at specific wave amplitudes. Furthermore, the results reveal that nonlinearity can profoundly influence the bandgap topology under specific parameters. This alteration can induce wave arrest and localization within the nonlinear phononic lattice, resulting in phenomena such as negative group velocity and break of reciprocity. To enhance the evaluation of elastoacoustic device performance, we also quantify the induced nonlinear energy scattering across different bands using a wavelet-based technique, which is valid for decomposition of multi-scale acoustics.

Mohammad Bukhari   Wayne State University
Alexander Vakakis   University of Illinois at Urbana-Champaign