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Shell-type acoustic metasurface and arc-shape carpet cloak
Fuyin Ma1, Yicai Xu2, Jiu Hui Wu2
1School of Mechanical Engineering & State Key Laboratory for Strength and Vibration of Mechanical Structure, Xi'an Jiaotong University, Xi'an, 71009, China. mafuyin@163.com.
Scientific Reports
|June 1, 2019
Summary
Researchers developed a novel thin shell acoustic metasurface for creating carpet cloaks. This acoustic metamaterial design enables cloaking of arbitrary shapes, advancing sound insulation and acoustic metamaterial applications.
Area of Science:
- Acoustics
- Materials Science
- Metamaterials
Background:
- Traditional acoustic metamaterials often utilize plate-type structures.
- Shell-type structures offer unique acoustic properties distinct from plate-type designs.
- Existing research primarily focuses on membrane- and plate-type acoustic metamaterials.
Purpose of the Study:
- To propose and investigate a thin shell-type acoustic metasurface for acoustic cloaking.
- To design a carpet cloak capable of closely covering arc-shaped objects for arbitrary shape concealment.
- To explore the acoustic properties and potential applications of shell-type acoustic metasurfaces.
Main Methods:
- Systematic proposal of thin shell-type acoustic metasurface designs.
- Experimental and calculated measurements of sound transmission loss (STL) for rotary spherical and ellipsoidal shell structures.
- Design and analysis of two-dimensional bilayer cylindrical and elliptic cylindrical shell structures.
- Development of an engineering iso-phase design method for phased compensation.
Main Results:
- Shell-type structures exhibit distinct sound insulation performance compared to plate-type structures.
- Shell-type cells demonstrate bianisotropic sound absorption, reflection, and effective parameters due to structural asymmetry.
- Nonlinear stiffness variation with radius of curvature observed, showing a wing shape tendency.
- Successful design of a bilayer cylindrical shell-type acoustic metasurface and an arc-shaped carpet acoustic cloak.
Conclusions:
- Thin shell-type acoustic metasurfaces offer a promising avenue for advanced acoustic cloaking applications.
- The proposed designs provide guidance for extending acoustic metamaterial research to shell-type structures.
- The developed arc-shaped cloak design supports the creation of cloaks for objects of arbitrary shapes.
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