A nonlinear dissipative elastic metamaterial for broadband wave mitigation

Nonlinearity and dissipation are two important aspects in elastic metamaterials that hold the potential to provide a novel method for the control of elastic waves. Here, we present a nonlinear dissipative elastic metamaterial in a triatomic mass-spring chain to explore the interplay between nonlinearity and dissipation for broadband wave attenuation. In the study, nonlinear stiffness is considered in the spring between the primary and secondary triatomic masses, and a damper is implemented in parallel to the tertiary spring. Various numerical tests on transient wave propagations are conducted, and show that the proposed design with properly selected nonlinear and damping parameters can generate broader wave attenuation regions compared with corresponding linear dissipative metamaterials and nonlinear non-dissipative metamaterials. We quantify the effects of nonlinearity and material damping in higher harmonic wave generations and wave energy absorption using narrow band incidences and demonstrate the application of the nonlinear dissipative triatomic lattice for blast wave mitigations. This work provides a novel approach to design materials capable of suppressing blast-induced shock waves or impact generated pulses that can cause severe local damage to nearby structures.