Acoustic Metamaterials Composed of Pre-stressed Oscillator Unit Cells and the Effective Method of Adjusting and Expanding Bandgap

The bandgap adjustment and expansion is an important research direction in acoustic metamaterial fields. This paper designs a kind of composed periodically arranging oscillator unit cells, proposes effective way to adjust the central frequencies widen frequency range bandgap. First, we design cell constructed by base structure, mass block, bending elastic beams connecting block with structure; then, study effect pre-stresses applying on characteristics metamaterials cells; finally, construct periodic combing three groups cells different pre-stresses, realize Our shows that, this has low-frequency broadband; can make shift towards low but will result narrow bandgap; combining effectively bandgap, overcoming limitation due pre-stresses.