title: Effects of locally resonant modes on underwater sound absorption in viscoelastic materials.
abstract: Recently, by introducing locally resonant scatterers with spherical shape proposed in phononic crystals into design of underwater sound absorption materials, the low-frequency underwater sound absorption phenomenon induced by the localized resonances is observed. To reveal this absorption mechanism, the effect of the locally resonant mode on underwater sound absorption should be studied. In this paper, the finite element method, which is testified efficiently by comparing the calculation results with those of the layer multiple scattering method, is introduced to investigate the dynamic modes and the corresponding sound absorption of localized resonance. The relationship between the resonance modes described with the displacement contours of one unit cell and the corresponding absorption spectra is discussed in detail, which shows that the localized resonance leads to the absorption peak, and the mode conversion from longitudinal to transverse waves at the second absorption peak is more efficient than that at the first one. Finally, to show the modeling capability of FEM and investigate shape effects of locally resonant scatterers on underwater sound absorption, the absorption properties of viscoelastic materials containing locally resonant scatterers with ellipsoidal shape are discussed.
authors: Key Laboratory of Photonic/Phononic Crystals of Ministry of Education,National University of Defense Technology, Changsha, Hunan, People's Republic of China, 410073. wenjihong@vip.sina.com
authors: Jihong
authors: J
authors: Wen
authors: Honggang
authors: H
authors: Zhao
authors: Linmei
authors: L
authors: Lv
authors: Bo
authors: B
authors: Yuan
authors: Gang
authors: G
authors: Wang
authors: Xisen
authors: X
authors: Wen
mesh_terms: D000042:Absorption; D000162:Acoustics / Q000295:instrumentation*; D004548:Elasticity; D004867:Equipment Design; D020342:Finite Element Analysis; D008962:Models, Theoretical; D009038:Motion; D009622:Noise / Q000517:prevention & control*; D009792:Oceans and Seas; D011108:Polymers / Q000737:chemistry*; D012542:Scattering, Radiation; D013016:Sound; D013997:Time Factors; D014732:Vibration; D014783:Viscosity
chemical_list: D011108:Polymers