Metamaterial beams with graded two-stage inertial amplification and elastic foundation

Isotacticity in chiral phononic crystals for low-frequency bandgap

“…Inspired by the inertial amplification, more and more novel studies are proposed. For instance, an octahedron structure was built to isolate the special omnidirectional elastic waves [40]; incorporating inertial amplification structures in continuous beams to manipulate the transverse wave [41,42]; a 2D thin plates embedded the classical inertial amplifier structures was proposed to modulate lowfrequency and broad lamb waves [43,44]; the low-frequency vibration isolation of the corrugated-core 3 / 26 sandwich panels can be enhanced through embedding the inertial amplification system [45]; a levertype inertial amplification system can achieve the broadband isolation for the surface wave which is induced by the seismic [46,47]; the combination of the inertial amplification and local resonance can improve the extremely narrow effective attenuation of the classical local resonance bandgap [48] and release the dependence on lowering stiffness and increasing mass for low-frequency local resonance bandgap [49]； the multiple, broadband and highly attenuative bandgaps can be obtained by a system with inertial amplification, local resonance, and Bragg scattering affect simultaneously [50]. However, in the last two decades, the design strategies [42,45,[51][52][53][54][55] have been limited to the form of the classical inertial amplification sub-structure.…”