Author
Nansha Gao
Other affiliations: Xi'an Jiaotong University, Nanyang Technological University
Bio: Nansha Gao is an academic researcher from Northwestern Polytechnical University. The author has contributed to research in topics: Metamaterial & Acoustics. The author has an hindex of 19, co-authored 55 publications receiving 1084 citations. Previous affiliations of Nansha Gao include Xi'an Jiaotong University & Nanyang Technological University.
Topics: Metamaterial, Acoustics, Vibration, Absorption (acoustics), Band gap
Papers
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TL;DR: Numerical simulations show that the V-folded acoustic black hole beam exhibits an ultra-wide complete bandgap below 1 kHz due to longitudinal-flexural waveform transformation, and experimental results verify this finding.
Abstract: This paper proposes a strategy to broaden complete bandgap attenuating flexural and longitudinal modes, and to shift them to lower frequencies by spatially folding designs. Numerical simulations show that the V-folded acoustic black hole beam exhibits an ultra-wide complete bandgap below 1 kHz due to longitudinal-flexural waveform transformation, and experimental results verify this finding. The proposed folded beams are easy-to-fabricate, of compact dimensions, and exhibit excellent wave attenuation functionality that makes them promising for low-frequency vibration reduction and wave attenuation applications.
117 citations
TL;DR: In this article, low frequency acoustic characteristics of mesophase pitch based carbon foams by impedance tube was studied and the porosity, density and micropore size of samples have a strong relationship with sound absorption capacity; increasing thickness of samples could heighten low frequency sound absorption coefficient, but increasement of back cavity would has almost no effects on low frequency.
106 citations
TL;DR: In this paper, a composite porous metamaterial (CPM) consisting in a porous polyurethane sponge with embedded multi-layer I-plates is proposed to mitigate the slow wave phenomenon and/or insufficient sub-wavelength sound absorption.
106 citations
TL;DR: In this article, the authors proposed a composite meta-porous structure embedded multiple lateral plates of different lengths, and investigated the corresponding sound absorption coefficients with the fixed and periodic boundary, which achieved high sound absorption in range of 0.6.4
102 citations
TL;DR: In this article, an underwater metamaterial for broadband acoustic absorption was proposed, which is composed of viscoelastic rubber, conical cavity, cylindrical oscillator and backing steel.
98 citations
Cited by
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TL;DR: To the best of our knowledge, there is only one application of mathematical modelling to face recognition as mentioned in this paper, and it is a face recognition problem that scarcely clamoured for attention before the computer age but, having surfaced, has attracted the attention of some fine minds.
Abstract: to be done in this area. Face recognition is a problem that scarcely clamoured for attention before the computer age but, having surfaced, has involved a wide range of techniques and has attracted the attention of some fine minds (David Mumford was a Fields Medallist in 1974). This singular application of mathematical modelling to a messy applied problem of obvious utility and importance but with no unique solution is a pretty one to share with students: perhaps, returning to the source of our opening quotation, we may invert Duncan's earlier observation, 'There is an art to find the mind's construction in the face!'.
3,015 citations
TL;DR: In this article, the recent progress in the design and fabrication of porous sound absorption materials is summarized and highlighted, and the review concludes with some perspectives and outlook for the porous materials.
343 citations
TL;DR: The Colony Predation Algorithm (CPA) as mentioned in this paper is based on the corporate predation of animals in nature and utilizes a mathematical mapping following the strategies used by animal hunting groups, such as dispersing prey, encircling prey, supporting the most likely successful hunter, and seeking another target.
263 citations
01 Jan 2010
TL;DR: In this article, the feasibility of tuning the band structure of phononic crystals is demonstrated by employing magnetostrictive materials and applying an external magnetic field, and the authors show the contactless tunability of the absolute band gaps of a two-dimensional phononic crystal composed of an epoxy matrix and Terfenol-D inclusions.
Abstract: The feasibility of tuning the band structure of phononic crystals is demonstrated by employing magnetostrictive materials and applying an external magnetic field. Band structures are calculated with a plane wave expansion method that accounts for coupling between the elastic behavior and the magnetic field through the development of elastic, piezomagnetic, and magnetic permeability effective tensors. We show the contactless tunability of the absolute band gaps of a two-dimensional phononic crystal composed of an epoxy matrix and Terfenol-D inclusions. The tunable phononic crystal behaves like a transmission switch for elastic waves when the magnitude of an applied magnetic field crosses a threshold.
165 citations
TL;DR: The acoustic black hole (ABH) as discussed by the authors is a technique for passive vibration control that was recently developed within the Structural Dynamics and Vibroacoustics communities, and it is achieved by embedding a local inhomogeneity in a thin-walled structure, typically a beam or a plate.
152 citations