DYNAMIC ANALYSIS OF METASTRUCTURE BEAM WITH LOW FREQUENCY MULTI-MODE RESONATORS

Metastructures with resonators are effective in wave attenuating due to band gaps, but it is still a challenge to realize low frequency multi-mode vibration suppression. A new low frequency multi-mode (LFMM) resonator, which consists of two-stage high-static-low-dynamic stiffness oscillators is proposed in this paper. The theoretical model of metastructure beam with LFMM resonator is established and band structures are obtained by the Plane Wave Expansion Method (PWEM). Then, the Wave Finite (WFEM) is combined with Periodic Structure Theory (PST) to calculate the forced response of the metastructure beam. WFEM is a powerful numerical tool of structure dynamics, which converts the study of the whole periodic structure into a single unit cell or small segment of the structure. Numeric results show that multiple low frequency band gaps are generated, in which the forced response is suppressed obviously, which means analytical and numerical method validate each other. Furthermore, dynamic analysis of a simplified unit cell show that number and location of band gaps is determined by LFMM resonator, which can be adjusted by configuring the physical parameters of the oscillators based on needs. Finally, the influence of mass ratio and damping of LFMM resonator on band gaps is also analyzed.status: publishe