Formation of band gaps in elastic metamaterials made of steel-pulp composite structures

Abstract

Noise and vibration performance is common requirement for engineering structure. Furthermore, such engineering structures need to employ the bio-based materials for reusability. This paper proposes elastic metamaterial made of pulp-steel composite structure whose periodic shapes prohibit the wave propagation in the frequency ranges referred as to band gap. As the molded pulp can manufacture the periodic shapes with low cost and low environmental burden, it has the potential to apply the elastic metamaterial for the mass-production. Wave propagation within the elastic metamaterial is modelled by wave finite method which provides dispersion curves of the elastic metamaterial. The calculated dispersion curves suggest that the elastic metamaterial made of pulp-steel composite structure can form the band gap related to the flexural waves. To demonstrate the vibration suppression in the band gap frequency, the frequency response of elastic metamaterial is measured using the those consisting of the four-unit cells, resulting that the frequency response is significantly reduced in the band gap frequency.