中国物理B ›› 2013, Vol. 22 ›› Issue (7): 74302-074302.doi: 10.1088/1674-1056/22/7/074302

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

Oblique incidence properties of locally resonant sonic materials with resonance and Bragg scattering effects

袁博, 温激鸿, 温熙森   

  1. Vibration and Acoustics Research Group, Laboratory of Science and Technology on Integrated Logistics Support,National University of Defense Technology, Changsha, 410073, China; MOE Key Laboratory of Photonic and Phononic Crystals, National University of Defense Technology, Changsha, 410073, China
  • 收稿日期:2012-09-21 修回日期:2012-10-30 出版日期:2013-06-01 发布日期:2013-06-01

Oblique incidence properties of locally resonant sonic materials with resonance and Bragg scattering effects

Yuan Bo (袁博), Wen Ji-Hong (温激鸿), Wen Xi-Sen (温熙森)   

  1. Vibration and Acoustics Research Group, Laboratory of Science and Technology on Integrated Logistics Support,National University of Defense Technology, Changsha, 410073, China; MOE Key Laboratory of Photonic and Phononic Crystals, National University of Defense Technology, Changsha, 410073, China
  • Received:2012-09-21 Revised:2012-10-30 Online:2013-06-01 Published:2013-06-01
  • Contact: Wen Xi-Sen E-mail:wenxs@vip.sina.com

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摘要： A locally resonant sonic material (LRSM) is an elastic matrix containing a periodic arrangement of identical local resonators (LRs), which can reflect strongly near their natural frequencies, where the wavelength in the matrix is still much larger than the structural periodicity. Due to the periodic arrangement, an LRSM can also display a Bragg scattering effect, which is a characteristic of phononic crystals. A specific LRSM which possesses both local resonance and Bragg scattering effects is presented. Via the layered-multiple-scattering theory, the complex band structure and the transmittance of such LRSM are discussed in detail. Through the analysis of the refraction behavior at the boundary of the composite, we find that the transmittance performance of an LRSM for oblique incidence depends on the refraction of its boundary and the transmission behaviors of different wave modes inside the composite. As a result, it is better to use some low-speed materials (compared with the speed of waves in surrounding medium) as the matrix of LRSM for designing sound blocking materials in underwater applications, since their acoustic properties are more robust to the incident angle. Finally, a gap-coupled LRSM with a broad sub-wavelength transmission gap is studied, whose acoustic performance is insensitive to the angle of incidence.

关键词: underwater acoustic materials, oblique incidence, locally resonant sonic materials, Bragg scattering

Abstract: A locally resonant sonic material (LRSM) is an elastic matrix containing a periodic arrangement of identical local resonators (LRs), which can reflect strongly near their natural frequencies, where the wavelength in the matrix is still much larger than the structural periodicity. Due to the periodic arrangement, an LRSM can also display a Bragg scattering effect, which is a characteristic of phononic crystals. A specific LRSM which possesses both local resonance and Bragg scattering effects is presented. Via the layered-multiple-scattering theory, the complex band structure and the transmittance of such LRSM are discussed in detail. Through the analysis of the refraction behavior at the boundary of the composite, we find that the transmittance performance of an LRSM for oblique incidence depends on the refraction of its boundary and the transmission behaviors of different wave modes inside the composite. As a result, it is better to use some low-speed materials (compared with the speed of waves in surrounding medium) as the matrix of LRSM for designing sound blocking materials in underwater applications, since their acoustic properties are more robust to the incident angle. Finally, a gap-coupled LRSM with a broad sub-wavelength transmission gap is studied, whose acoustic performance is insensitive to the angle of incidence.

Key words: underwater acoustic materials, oblique incidence, locally resonant sonic materials, Bragg scattering

中图分类号:  (Ultrasonics, quantum acoustics, and physical effects of sound)

  • 43.35.+d
43.30.+m (Underwater sound) 43.20.+g (General linear acoustics) 43.40.+s (Structural acoustics and vibration)