Band-gap tunable dielectric elastomer filter for low frequency noise

Because of the position of the motor and the excitation of the suspension system, a wheel-driven electric bus produces low-frequency noise, which is difficult to resolve through traditional sound absorption and noise reduction technology. Through an interior noise test of a wheel-driven electric bus, we found that the interior low-frequency noise had a considerable influence on the driver. In order to solve this problem, a locally resonant phononic crystal was used to meet the requirements of vibration and noise reduction for the wheel-driven electric bus. The intrinsic relationship between the band gap distribution of the locally resonant phononic crystal and the topology was established by training a neural network, so as to achieve the desired effect of the bandgap model on the basis of the input bandgap range. Upon an increase in the number of models, the prediction model error decreased gradually. This method could quickly obtain the structural parameters of the locally resonant phononic crystal with the expected band gap, which made it convenient to apply locally resonant phononic crystals to the vibration and noise reduction of wheel-driven electric buses and in other fields.

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Effect of Cavity Structure on Acoustic Characteristics of Phononic Crystals Based on Double-Layer Plates

Crystals ◽

10.3390/cryst10110995 ◽

2020 ◽

Vol 10 (11) ◽

pp. 995

Author(s):

Chuanmin Chen ◽

Zhaofeng Guo ◽

Songtao Liu ◽

Hongda Feng ◽

Chuanxi Qiao

Keyword(s):

Noise Reduction ◽

Band Gap ◽

Double Layer ◽

Transmission Loss ◽

Low Frequency ◽

Phononic Crystals ◽

Frequency Noise ◽

Structural Factors ◽

Low Frequency Noise ◽

Cavity Structure

Localized resonance phononic crystals (LRPCs) are increasingly attracting scientists’ attention in the field of low-frequency noise reduction because of the excellent subwavelength band gap characteristics in the low-frequency band. However, the LRPCs have always had the disadvantage that the noise reduction band is too narrow. In this paper, in order to solve this problem, LRPCs based on double-layer plates with cavity structures are designed. First, the energy bands of phononic crystals plate with different thicknesses were calculated by the finite element method (FEM). At the same time, the mechanism of band gap generation was analyzed in combination with the modalities. Additionally, the influence of structure on the sound transmission loss (STL) of the phononic crystals plate and the phononic crystals cavity plates were analyzed, which indicates that the phononic crystals cavity plates have notable characteristics and advantages. Moreover, this study reveals a unique ”cavity cave” pattern in the STL diagram for the phononic crystals cavity plates, and it was analyzed. Finally, the influence of structural factors on the band structure and STL of phononic crystals cavity plates are summarized, and the theoretical basis and method guidance for the study of phononic crystals cavity plates are provided. New ideas are also provided for the future design and research of phononic crystals plate along with potential applications in low-frequency noise reduction.

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Control of low-frequency noise for piping systems via the design of coupled band gap of acoustic metamaterials

Physics Letters A ◽

10.1016/j.physleta.2016.05.017 ◽

2016 ◽

Vol 380 (29-30) ◽

pp. 2322-2328 ◽

Cited By ~ 14

Author(s):

Yanfei Li ◽

Huijie Shen ◽

Linke Zhang ◽

Yongsheng Su ◽

Dianlong Yu

Keyword(s):

Band Gap ◽

Low Frequency ◽

Frequency Noise ◽

Acoustic Metamaterials ◽

Low Frequency Noise ◽

Piping Systems

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INVESTIGATION OF LOW-FREQUENCY NOISE IN HETEROSTRUCTURE FIELD-EFFECT TRANSISTORS BASED ON WIDE BAND GAP SEMICONDUCTORS

Noise in Physical Systems and 1/F Fluctuations ◽

10.1142/9789812811165_0051 ◽

2001 ◽

Author(s):

ALEXANDER A. BALANDIN

Keyword(s):

Band Gap ◽

Field Effect ◽

Field Effect Transistors ◽

Low Frequency ◽

Wide Band ◽

Frequency Noise ◽

Low Frequency Noise ◽

Wide Band Gap ◽

Heterostructure Field Effect Transistors ◽

Wide Band Gap Semiconductors

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Study on Locally Resonant Phononic Crystals Based on Automotive Noise Control

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.299-300.1208 ◽

2011 ◽

Vol 299-300 ◽

pp. 1208-1211

Author(s):

Yu Yang He ◽

Xiao Xiong Jin ◽

Huan Wei

Keyword(s):

Band Gap ◽

Noise Control ◽

Low Frequency ◽

Simulation Method ◽

Phononic Crystals ◽

Simplified Model ◽

Frequency Noise ◽

Two Dimensional ◽

Low Frequency Noise ◽

The Impact

Automotive low frequency noise is difficult to control in a traditional way. Locally resonant phononic crystals (PCs) can forbid the propagation of certain frequency. This PCs’ structure also can be fabricated to apply in automotive noise control. The simulation method is applied to establish the model of two-dimensional (2D) locally resonant phononic crystals in order to research the impact of the parameters on the propagation. The band gap of locally resonant phononic crystals in z mode is calculated using the simplified model.

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