Formation of band gaps in periodic composite beams by finite element analysis

Abstract

It is known that a filtering phenomenon, called a band gap, occurs in structures in which materials or structures with different properties are repeated, and vibration propagation is suppressed in the band gap frequency. This study intends to realize the band gap phenomena using composite beams consisting of metallic materials. First, the wave finite element analysis (WFEM) is applied to derive a dispersion curve, which indicated the conditions for the formation of a band gap. Next, by comparing the results of frequency response analysis using Ansys, the formation of band gaps is confirmed by showing no resonant peaks exist in the frequency bands where band gaps are predicted. By evaluating several periodic composite beams, it was found that the condition for widening the frequency band in which the band gap is formed is a large difference between the EI/ρA values of the two phases. Furthermore, by replacing the hollow beams with solid beams with ρA and EI set to be equivalent, it was shown that it is possible to predict the formation of a band gap by dispersion analysis using WFEM for beams with a complex structure.