Beam-type metastructure with X-shape inertial amplification mechanisms for vibration suppression

A new type of beam-type metastructure periodically attaching single- or multi-stage X-shape inertial amplification (XIA) mechanisms is designed to realize efficient elastic wave attenuation and wide bandgaps benefiting the vibration suppression. Band structures of the unit cell and vibration response of the finite beam are validated numerically and experimentally. Numerical results show that compared with the triangular inertial amplification beams with the same added masses, XIA mechanisms generate wider bandgaps with higher attenuation constants at the same frequency band, for the same inertia amplification (IA) angle or same installation space. Parametric studies reveal that XIA mechanisms lead to the coupling effect of transverse wave and longitudinal wave, and induce a newly emerging bandgap. Moreover, the variations of IA angle, amplification ratio and number of stages apply basically similar effects on band structures, except the IA span. Finally, in order to explore practical applications on vibration suppression of XIA mechanisms, two schemes of multiple mechanisms in a unit cell and the hybrid unit cell are investigated. The proposed designs of XIA mechanisms have the potential to improve the capability of vibration suppression of the structures in engineering practices.