Effect of prestress on phononic band gaps induced by inertial amplification

Phononic crystals and elastic metamaterials have recently received significant attention due to their potential for unconventional wave control. Despite this interest, one outstanding issue is that band diagram typically fixed once the structure designed. To overcome limitation, periodic structures with adaptive properties been proposed Bragg- local resonance-driven structures. In context, we report about effect of an applied external mechanical load on a exhibiting gaps induced by inertial amplification mechanism. If compared cases Bragg scattering ordinary resonant metamaterials, observe here more remarkable curve shift, modulated through large but fully reversible compression (stretch) unit cell, eventually triggering (up two times) enlargement (reduction) width specific gap. An important up (down)-shift some dispersion branches over wavenumber values also observed, showing selective variation may lead negative group velocities larger (smaller) ranges. addition, possibility non-monotone trend lower limit first BG under same type prestrain found explained analytical model, which unequivocally proves behaviour derives from different cell effective mass stiffness variations as level increases. These peculiarities derive hinge-like regions typical The prestress investigated development 2-step calculation method: first, Updated Lagrangian scheme, including static geometrically nonlinear analysis representative undergoing action derived, then Floquet-Bloch decomposition linearized equations acousto-elasticity in deformed configuration. Finally, most evident consequence curves application prestress, i.e. gap shift respect unloaded structure, demonstrated transient numerical simulations, clearly proving capability switch pass- stop-band frequency range. results presented herein provide insights amplification, suggest new opportunities real-time tunable manipulation.