题目：Investigation on the bandgap properties and vibration isolation performances of metalattice structures
The discrete acoustic metamaterial (AM) models composed of mass-spring subsystems with multi or graded resonators and the continuous AM-based lattice model including a cross type core consisting of two segments namely with a radius jump discontinuity at the midspan in each rod are proposed. Wave propagation in the models is studied to investigate the dispersion relations and vibration bandgaps. Three dimensional (3D) AM-based metalattice structures consisting of beams were fabricated by selective laser sintering (SLS)-based 3D-printing technology. The bandgaps induced by local resonances and waveform transformations are obtained by calculating the band structure of the AM-based lattice structure using finite-element (FE) simulations and the results are verified by conducting experiments about vibration transmission.