Low-frequency flexural wave attenuation in metamaterial sandwich beam with hourglass lattice truss core

Though lightweight sandwich structures have been extensively applied in practical engineering, it remains a challenge to control wave propagation and vibration in these structures in a low-frequency range. In this work, the band structure of flexural waves in a metamaterial sandwich beam (MSB) with hourglass lattice truss core is investigated using the transfer matrix method (TMM). The hourglass truss structure with lumped masses is modelled as a series of local resonators with determined equivalent stiffnesses and masses. A metamaterial dual-beam (MDB) model is then established to describe the MSB, and the MDB model is noted to be equivalent to the conventional metamaterial beam (CMB) model under base excitation. The MSB is further studied directly by the finite element method that confirmed the MSB can be represented by the CMB through the transmittance analysis and band structure analysis. Subsequently, parametric study is performed to investigate the effects of the material and structural parameters on the band structures of the MSB. This work provides a roadmap of modelling of lightweight lattice sandwich beams with complex core structures and presents guidelines for applying sandwich beams to control wave propagation. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The band structure of flexural waves in a metamaterial sandwich beam (MSB) with hourglass lattice truss core was investigated using the transfer matrix method, and the effects of material and structural parameters on the band structures were studied. The research provides insights into modeling and controlling wave propagation in lightweight lattice sandwich beams.