中国物理B ›› 2015, Vol. 24 ›› Issue (8): 84301-084301.doi: 10.1088/1674-1056/24/8/084301

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

Effects of core position of locally resonant scatterers on low-frequency acoustic absorption in viscoelastic panel

钟杰, 温激鸿, 赵宏刚, 尹剑飞, 杨海滨   

  1. Vibration and Acoustics Research Group, Laboratory of Science and Technology on Integrated Logistics Support, National University of Defense Technology, Changsha 410073, China
  • 收稿日期:2014-04-28 修回日期:2015-01-11 出版日期:2015-08-05 发布日期:2015-08-05
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 51275519).

Effects of core position of locally resonant scatterers on low-frequency acoustic absorption in viscoelastic panel

Zhong Jie (钟杰), Wen Ji-Hong (温激鸿), Zhao Hong-Gang (赵宏刚), Yin Jian-Fei (尹剑飞), Yang Hai-Bin (杨海滨)   

  1. Vibration and Acoustics Research Group, Laboratory of Science and Technology on Integrated Logistics Support, National University of Defense Technology, Changsha 410073, China
  • Received:2014-04-28 Revised:2015-01-11 Online:2015-08-05 Published:2015-08-05
  • Contact: Wen Ji-Hong E-mail:wenjihong@vip.sina.com
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 51275519).

摘要:

Locally resonant sonic materials, due to their ability to control the propagation of low-frequency elastic waves, have become a promising option for underwater sound absorption materials. In this paper, the finite element method is used to investigate the absorption characteristics of a viscoelastic panel periodically embedded with a type of infinite-long non-coaxially cylindrical locally resonant scatterers (LRSs). The effect of the core position in the coating layer of the LRS on the low-frequency (500 Hz–3000 Hz) sound absorption property is investigated. With increasing the longitudinal core eccentricity e, there occur few changes in the absorptance at the frequencies below 1500 Hz, however, the absorptance above 1500 Hz becomes gradually better and the valid absorption (with absorptance above 0.8) frequency band (VAFB) of the viscoelastic panel becomes accordingly broader. The absorption mechanism is revealed by using the displacement field maps of the viscoelastic panel and the steel slab. The results show two typical resonance modes. One is the overall resonance mode (ORM) caused by steel backing, and the other is the core resonance mode (CRM) caused by LRS. The absorptance of the viscoelastic panel by ORM is induced mainly by the vibration of the steel slab and affected little by core position. On the contrary, with increasing the core eccentricity, the CRM shifts toward high frequency band and decouples with the ORM, leading to two separate absorption peaks and the broadened VAFB of the panel.

关键词: finite element method, non-coaxially cylindrical locally resonant scatterers, core position, sound absorption

Abstract:

Locally resonant sonic materials, due to their ability to control the propagation of low-frequency elastic waves, have become a promising option for underwater sound absorption materials. In this paper, the finite element method is used to investigate the absorption characteristics of a viscoelastic panel periodically embedded with a type of infinite-long non-coaxially cylindrical locally resonant scatterers (LRSs). The effect of the core position in the coating layer of the LRS on the low-frequency (500 Hz–3000 Hz) sound absorption property is investigated. With increasing the longitudinal core eccentricity e, there occur few changes in the absorptance at the frequencies below 1500 Hz, however, the absorptance above 1500 Hz becomes gradually better and the valid absorption (with absorptance above 0.8) frequency band (VAFB) of the viscoelastic panel becomes accordingly broader. The absorption mechanism is revealed by using the displacement field maps of the viscoelastic panel and the steel slab. The results show two typical resonance modes. One is the overall resonance mode (ORM) caused by steel backing, and the other is the core resonance mode (CRM) caused by LRS. The absorptance of the viscoelastic panel by ORM is induced mainly by the vibration of the steel slab and affected little by core position. On the contrary, with increasing the core eccentricity, the CRM shifts toward high frequency band and decouples with the ORM, leading to two separate absorption peaks and the broadened VAFB of the panel.

Key words: finite element method, non-coaxially cylindrical locally resonant scatterers, core position, sound absorption

中图分类号:  (General linear acoustics)

  • 43.20.+g
43.30.+m (Underwater sound)