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Tunable negative elastic modulus acoustic metamaterial

An acoustic metamaterial, elastic modulus technology, applied in the field of acoustic metamaterials

Inactive Publication Date: 2012-07-11
NORTHWESTERN POLYTECHNICAL UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, it is difficult for a negative structure with a single-frequency response to couple with another negative structure. Therefore, the preparation of a frequency-tunable negative acoustic metamaterial has become the primary problem to be solved at present.

Method used

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  • Tunable negative elastic modulus acoustic metamaterial
  • Tunable negative elastic modulus acoustic metamaterial
  • Tunable negative elastic modulus acoustic metamaterial

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] First: use mechanical drilling technology to drill a hole with a diameter of 2.5mm on one side of a polystyrene plastic hollow ball with a diameter of 10mm and a wall thickness of 0.5mm; secondly: prepare a sponge with a diameter of 30mm and a thickness of 25mm as a substrate; finally: put The prepared open hollow sphere is placed in the center of the sponge substrate, thus the SHS acoustic metamaterial is prepared, as figure 1 shown. In addition, the internal medium of the open hollow sphere see figure 2 (a), the water content is 0 vol%. The acoustic transmission curve of this metamaterial is as follows image 3 shown.

Embodiment 2

[0015] First: use mechanical drilling technology to drill a hole with a diameter of 2.5mm on one side of a polystyrene plastic hollow ball with a diameter of 10mm and a wall thickness of 0.5mm; secondly: prepare a sponge with a diameter of 30mm and a thickness of 25mm as a substrate; finally: put The prepared open hollow sphere is placed in the center of the sponge substrate, thus the SHS acoustic metamaterial is prepared, as figure 1 shown. In addition, the internal medium of the open hollow sphere see figure 2 (b), the content of water is 62.5vol%. The acoustic transmission curve of this metamaterial is as follows image 3 shown.

Embodiment 3

[0017] First: use mechanical drilling technology to drill a hole with a diameter of 4mm on one side of a polystyrene plastic hollow ball with a diameter of 10mm and a wall thickness of 0.5mm; secondly: prepare a sponge with a diameter of 30mm and a thickness of 25mm as a substrate; finally: prepare The open hollow sphere is placed in the center of the sponge substrate, thus the SHS acoustic metamaterial is prepared, just as figure 1 shown. In addition, the internal medium of the open hollow sphere see figure 2 (a), the water content is 0 vol%. The acoustic transmission curve of this metamaterial is as follows Figure 4 shown.

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Abstract

The invention relates to a negative elastic modulus acoustic metamaterial based on a spilt hollow sphere, in particular to a tunable negative elastic modulus acoustic metamaterial. The structural unit is a spilt hollow sphere (SHS) structure; and through changing the inside component, namely changing the tunable frequency band of an air and water composite medium component, the negative elastic modulus material with tunability is realized. In addition, a research shows that the tunable range of the SHS is widened on the basis that after a steel ball in added into the SHS, the changed volume percentage of water is changed. A tuning method provided by the invention is simple, and can conveniently realize resonance at different frequency bands.

Description

technical field [0001] The invention relates to a negative elastic modulus acoustic metamaterial, in particular to a tunable negative elastic modulus acoustic metamaterial. Background technique [0002] Left-handed materials refer to a kind of artificial coal quality that is periodically arranged in space by electric and magnetic resonance units. Anomalous Doppler effect, cloaking and perfect lens effect, etc. In the field of electromagnetism, combining the two structures of periodically arranged split resonator rings (SRRs) and metal rods can yield left-handed materials with both negative magnetic permeability and permittivity. Due to the similarity between electromagnetic waves and acoustic waves, it has been confirmed theoretically and experimentally that acoustic metamaterials can exhibit negative elastic modulus or negative mass density. Acoustic metamaterials with negative mass densities are generally realized by spring oscillator systems or membranes. On the other ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G10K11/162G10K11/172
Inventor 赵晓鹏郝丽梅丁昌林
Owner NORTHWESTERN POLYTECHNICAL UNIV
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