Article
Engineering, Mechanical
Yi Zeng, Liyun Cao, Sheng Wan, Tong Guo, Yan-Feng Wang, Qiu-Jiao Du, Badreddine Assouar, Yue-Sheng Wang
Summary: Seismic metamaterials have received significant attention in the past two decades due to their ability to control seismic surface waves. In this study, a new type of seismic metamaterial with a low-frequency bandgap induced by inertial amplification is proposed to isolate seismic surface waves. Experimental results using a metamaterial plate composed of 25 unit cells demonstrate the characteristics of the bandgap induced by inertial amplification. The imaging of flexural waves by a scanning laser Doppler vibrometer shows strong attenuation effects in the bandgap caused by the metamaterial plate. The broadband attenuation is investigated using two different types of unit cells. Finally, similar structures with inertial amplification are introduced to design seismic metamaterials for isolating seismic surface waves at low frequencies.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Mechanical
Yifei Xu, Zhigang Cao, Kemeng Cui, Yuanqiang Cai, Xingbo Pu
Summary: In this study, an original analytical formulation is proposed to investigate the interaction between seismic Love waves and a metasurface composed of tunable anti-plane resonators. The formulation utilizes the Green's function to describe the incident and scattered fields and derives a dispersion relation for hybrid Love waves using the effective medium approximation. The capabilities of the analytical formulation are demonstrated through modeling Love waves propagating across resonators, revealing complex phenomena and hybridization features.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Engineering, Civil
Yu-Chi Su, Yu-Jen Wang, Yu-Ching Chou, Kuan-Teng Lin
Summary: This study proposes two novel seismic metamaterials models, trophy and apple core, inspired by an ancient Chinese puzzle. Bandgaps below 15Hz are achieved by exclusively using concrete as the base material in the designs. Vibration modes are investigated to clarify the bandgap formation.
INTERNATIONAL JOURNAL OF STRUCTURAL STABILITY AND DYNAMICS
(2023)
Article
Mechanics
Farhad Zeighami, Antonio Palermo, Athanasios Vratsikidis, Zhibao Cheng, Dimitris Pitilakis, Alessandro Marzani
Summary: The study assessed the attenuation performance of a medium-scale resonant wave barrier operating within the frequency range of 50-100 Hz, showing that the local resonant barrier can effectively reduce the surface wave amplitude near the resonant frequency. Multiple-frequency barriers were designed to expand the attenuation frequency band.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2021)
Article
Chemistry, Physical
Yu-Chi Su, Sheng-Shiang Wang
Summary: Seismic metamaterials offer an innovative approach to earthquake engineering by reducing the impact of seismic waves without modifying existing structures. This study proposes two novel designs, V- and N-shaped, to achieve a broad bandgap at low frequencies. By adding a line to the letter V, the bandgap can be broadened in the N-shaped design. These designs, arranged in a gradient pattern, combine the bandgaps of metamaterials with different heights. The use of concrete as the base material makes the proposed seismic metamaterial cost-effective. Finite element transient analysis and band structures confirm the accuracy of the numerical simulations, showing effective attenuation of surface waves across a wide range of low frequencies using the gradient V- and N-shaped seismic metamaterials.
Article
Engineering, Civil
Muhammad, C. W. Lim, Krzysztof Kamil Zur
Summary: This study proposes two types of engineered resonant metabarrier designs for attenuating ground born vibrations in the subwavelength frequency region, which can potentially be used to protect infrastructures from earthquake hazards. The effectiveness of the metabarriers in attenuating incoming Rayleigh surface waves is investigated through analytical and numerical models, with findings indicating an extremely wide low frequency bandgap for Rayleigh wave attenuation.
ENGINEERING STRUCTURES
(2021)
Article
Multidisciplinary Sciences
Qi Cao, Yongjiang Li, Hong Zhang, Jiabao Yang, Jian Han, Ting Xu, Shuangjie Wang, Zishuai Wang, Bingyu Gao, Junsong Zhao, Xiaoqiang Li, Xiaoyan Ma, Shaik Mohammed Zakeeruddin, Wei E. Sha, Xuanhua Li, Michael Graetzel
Summary: This study introduces a star-shaped polymer to enhance charge transport and inhibit ion migration in perovskite solar cells, leading to improved efficiency and stability. Modified devices demonstrate significant performance enhancements and excellent long-term operational stability.
Article
Forestry
Muhammad, C. W. Lim
Summary: This study investigates the seismic mitigation mechanism of clusters of forest trees, achieving a wide locally resonant bandgap through the interaction between Rayleigh waves and trees. It is found that bulky side branches of trees play a positive role in enhancing coupling strength, and the performance and efficiency of the bandgap are validated using a finite element method.
TREES-STRUCTURE AND FUNCTION
(2021)
Article
Engineering, Multidisciplinary
Zhongxian Liu, Mingkai Zhang, Lei Huang, Hai Zhang
Summary: In this study, a fast multipole indirect boundary element method (FM-IBEM) is developed to study the scattering of seismic waves by 3-D seismic metamaterials (SMs), and a 3-D rock soil composite seismic metamaterial (RSCSM) is proposed. The FM-IBEM with fast multipole expansion technique is able to effectively solve the broadband scattering problem of seismic waves by large-scale SMs. The RSCSM demonstrates a significant isolation effect and can attenuate the ultralow frequency of a seismic wave.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2023)
Article
Materials Science, Multidisciplinary
Weiwei Wang, Wei Guan, Yifan Dou, Yan Zhou
Summary: In this paper, an embedded seismic metamaterial with an ultra-low-frequency bandgap is proposed to analyze the attenuation of low-frequency seismic surface waves. The results show that there are vibration modes with energy concentrated in the SM and near the surface in the range of 0-1.3 Hz, while the surface wave attenuates in the range of 1.3-20 Hz.
MECHANICS OF ADVANCED MATERIALS AND STRUCTURES
(2023)
Article
Multidisciplinary Sciences
Selcuk Kacin, Murat Ozturk, Umur Korkut Sevim, Muharrem Karaaslan, Oguzhan Akgol, Zafer Ozer, Mustafa Demirci, Emin Unal, Bayram Ali Mert, Maide Erdogan Alkurt, Fatih Ozkan Alkurt, Mustafa Tunahan Basar, Seyda Gulsum Kaya
Summary: This study investigates the effects of seismic metamaterials formed using circular array concrete piles on surface waves. Numerical analysis using the finite element method (FEM) was conducted to determine optimum dimensions, and these dimensions were applied in the experimental field. The results show that the proposed structure effectively prevents the propagation of seismic surface waves.
Article
Mechanics
Yingli Li, Ahmed Opeyemi Jamiu, Muhammad Zahradeen Tijjani
Summary: In this study, the elastic wave propagation behavior of a diamond-shaped metastructure was investigated analytically and numerically. The metastructure's dispersion relation was derived based on Bloch's theorem, and the transmittance of the metastructure with finite periods was studied. Various extreme cases of lattice structure parameters were examined to analyze different configuration effects. The validity of the finite element solution was confirmed through a vibration experiment on a 3D printed specimen. The proposed metastructure has potential applications in vibration isolator design.
ARCHIVE OF APPLIED MECHANICS
(2023)
Article
Acoustics
Muhammad Muzamil, Hongwu Yang, Rui Xu, Yi Zeng, Pai Peng, Qiujiao Du
Summary: This study aims to increase the bandwidth of earthquake prevention by improving the cylindrical resonant structure. The results show that the proposed structure provides a low-frequency wide bandgap in homogeneous soil, and an additional bandgap in the lower frequency region in stratified soil.
Article
Engineering, Civil
Yi Wang, Fang Yang, Jin-Shui Yang, Li-Li Tong, Shuang Li, Qi Liu, Gang-Ling Hou, Pei-Dong Sun, Mian Xing, Gang Zheng
Summary: Based on numerical simulation and experiments, a petal-shaped seismic metamaterial is proposed to change the internal scatterer into a structure consisting of four sectors. This structure can form an ultra-low frequency bandgap to effectively attenuate seismic waves and has potential applications in seismic isolation and attenuation of buildings.
Article
Engineering, Electrical & Electronic
Jin Zhou, Xiaoshan Liu, Houjiao Zhang, Mulin Liu, Qing Yi, Zhengqi Liu, Junqiao Wang
Summary: A scheme for ultra-broadband and polarization-insensitive metamaterial perfect absorber using thin metal-insulator-metal (MIM) stack with titanium resonators is proposed. The absorber shows strong absorption of electromagnetic waves in a wavelength range of 400-2500 nm, with a high spectral average absorptivity of 93.8% and maximal absorptivity of 99.8%. The use of titanium instead of noble metals reduces fabrication cost and enhances thermal stability and biocompatibility, paving the way for various applications.
IEEE PHOTONICS JOURNAL
(2021)
Article
Engineering, Mechanical
Ting-Ting Wang, Yan-Feng Wang, Zi-Chen Deng, Vincent Laude, Yue-Sheng Wang
Summary: Two-dimensional phononic metaplates with a periodic array of cups on a thin epoxy plate were investigated, leading to the creation of reconfigurable phononic waveguides. Straight and 90 degrees bent waveguides were experimentally considered. Experimental results were compared to a three-dimensional finite element model of fluid-structure interaction, showing the potential for practical design of multiplexed and programmable acoustic devices implemented with reconfigurable waveguides printed on demand in a phononic metaplate.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Review
Mechanics
A-Li Chen, Yue-Sheng Wang, Yan-Feng Wang, Hong-Tao Zhou, Si-Min Yuan
Summary: This review summarizes recent developments in acoustic/elastic metasurfaces and outlines future research directions in this field.
APPLIED MECHANICS REVIEWS
(2022)
Article
Engineering, Mechanical
Xiao-Shuang Li, Yan-Feng Wang, Yue-Sheng Wang
Summary: In this study, a sparse binary elastic metasurface (SBEMs) is designed to regulate flexural waves, and its effectiveness and enhanced energy output capability are demonstrated through experiments. This design strategy provides a new approach for tailoring flexural waves.
EXTREME MECHANICS LETTERS
(2022)
Article
Physics, Applied
Yi Zeng, Liyun Cao, Sheng Wan, Tong Guo, Shuowei An, Yan-Feng Wang, Qiu-Jiao Du, Brice Vincent, Yue-Sheng Wang, Badreddine Assouar
Summary: This letter introduces a seismic metamaterial with an ultra-low frequency bandgap induced by inertial amplification. Numerical and experimental results demonstrate that the proposed metamaterial can effectively isolate seismic surface waves. Additionally, an embedded inertial amplification mechanism is introduced on a soil substrate to design a seismic metamaterial capable of attenuating seismic waves around 4Hz.
APPLIED PHYSICS LETTERS
(2022)
Article
Engineering, Mechanical
Wei Guo, Shu-Yan Zhang, Yan-Feng Wang, Vincent Laude, Yue-Sheng Wang
Summary: The propagation of evanescent Lamb waves in the one-dimensional viscoelastic phononic metastrip is studied in this paper. The effect of viscosity, different cutting forms, and material properties on the complex band structure and wave distribution is investigated. The results provide a numerical and experimental foundation for practical applications of phononic metastrips.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Mechanical
Hong-Tao Zhou, Wen-Xiao Fu, Xiao-Shuang Li, Yan-Feng Wang, Yue-Sheng Wang
Summary: In this work, a loosely coupled reflective impedance waterborne acoustic metasurface (WAM) is proposed, enabling precise manipulation of waterborne sound. A function-structure integrated topology optimization framework is established to design WAMs by weakening vibration coupling between solid units through local resonance. Various customized waterborne sound fields are successfully achieved, demonstrating the feasibility and effectiveness of the design strategy. The inverse-design WAMs exhibit good robustness to operating frequency, incident angle, and geometrical shape.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Mechanics
Ting-Ting Wang, Yan-Feng Wang, Zi-Chen Deng, Vincent Laude, Yue-Sheng Wang
Summary: In this study, we investigated the propagation of acoustoelastic waves in a two-dimensional phononic metaplate through numerical simulations and experiments. By selectively emptying certain cups, reconfigurable coupled-resonator acoustoelastic waveguides were created, and the 90 degrees bent waveguides and the collective resonances of the aperiodic chain were observed. The experimental results were compared to a three-dimensional finite element model, taking fluid-structure interaction into account. This study demonstrates the potential for designing reconfigurable and programmable elastic wave devices.
COMPOSITE STRUCTURES
(2023)
Article
Physics, Applied
Yifan Zhu, Aurelien Merkel, Liyun Cao, Yi Zeng, Sheng Wan, Tong Guo, Zihao Su, Siyuan Gao, Haohan Zeng, Hui Zhang, Badreddine Assouar
Summary: Numerically and experimentally, we demonstrate the acoustic analogue of super-Klein tunneling in a heterojunction of phononic crystals with Willis scatterers that possess pseudospin-1 Dirac cones. Unlike the pseudospin-1/2 Dirac cones, the pseudospin-1 cones require an additional flatband across the Dirac points in the band structure. The observed super-Klein tunneling in pseudospin-1 systems refers to perfect transmission at one specific frequency and all incidence angles within the energy barrier, which has significant implications for exploring the physics of pseudospin-1 quasiparticles.
APPLIED PHYSICS LETTERS
(2023)
Article
Engineering, Mechanical
Shu-Yan Zhang, Jia-Chen Luo, Yan-Feng Wang, Vincent Laude, Yue-Sheng Wang
Summary: The study investigates the propagation of evanescent waves in hybrid poroelastic metamaterials by considering interface effects. Finite element model is established for elastic/poroelastic and fluid/poroelastic interfaces, and general forms for Bloch's theorem are obtained to calculate the complex band structure and frequency response of hybrid metamaterials. The study discusses the influence of geometrical and material parameters, as well as the viscosity of the pore fluid on the propagation of elastic waves. The results and discussions show the appearance of flat bands, locally resonant band gaps, and a transition from avoided crossing to wave-number band gaps, among other findings.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Chemistry, Multidisciplinary
Hong-Tao Zhou, Shao-Cong Zhang, Tong Zhu, Yu-Ze Tian, Yan-Feng Wang, Yue-Sheng Wang
Summary: Extreme impedance mismatch at water-air interfaces hampers cross-media applications such as ocean-air wireless acoustic communication. By employing impedance-matched hybrid metasurfaces assisted by topology optimization, independent sound transmission enhancement and phase modulation across the water-air interface are achieved. Experimental results show significant improvements in transmitted amplitude, with an enhancement of approximately 25.9 dB compared to the bare water-air interface and up to 42 dB with axial focusing function, enabling various customized vortex beams and promoting applications in ocean-air communication.
Article
Multidisciplinary Sciences
Liyun Cao, Sheng Wan, Yi Zeng, Yifan Zhu, Badreddine Assouar
Summary: This study reports the existence of phononic skyrmions, new topological structures formed by the hybrid spin of elastic waves. The frequency-independent spin configuration of these skyrmions leads to ultra-broadband features and can be produced in any solid structure, including chip-scale ones. The experiment also demonstrates the robustness of phononic skyrmion lattices against local defects, sharp corners, and rectangular holes. This research opens up new possibilities for elastic wave manipulation and structuration through spin configuration and offers promising applications in phononic technologies.
Article
Physics, Applied
Yu-Ze Tian, Xiao-Lei Tang, Yan-Feng Wang, Vincent Laude, Yue-Sheng Wang
Summary: Extensive research has been conducted on the design of metasurfaces, particularly focusing on strategies based on impedance theory. In this study, an annular acoustic impedance metasurface is introduced in a cylindrical shell waveguide for encrypted information storage. Numerical simulation and experimental verification demonstrate the successful retrieval of hidden messages. The findings of this work are expected to contribute to the development of impedance metasurfaces in acoustic holography and encrypted acoustic communications.
PHYSICAL REVIEW APPLIED
(2023)
Article
Materials Science, Multidisciplinary
Vincent Laude, Yan-Feng Wang
Summary: Open phononic systems in unbounded media can support localized phonons with complex frequencies. The concept of elastic quasinormal modes (QNMs) is introduced to describe these systems, similar to nanophotonic and plasmonic open systems. A complex, unconjugated form of reciprocity theorem for elastodynamics is used to accurately approximate the response function based on the elastic QNM basis. The elastic Purcell effect is then described by a complex-valued modal volume for each QNM. Validation is performed through simulations of vibrating nylon rod, slender nickel ridge, and nanoscale tuning fork, all showing agreement with the elastodynamic equation.
Article
Physics, Applied
Xiao-Tong Gong, Hong-Tao Zhou, Shao-Cong Zhang, Yan-Feng Wang, Yue-Sheng Wang
Summary: Based on the resonances of bubbles, this study proposes a metasurface consisting of bubbles sealed with membranes to achieve perfect sound transmission at the water-air interface. The experimental results show significant sound transmission enhancement at specific frequencies, and the metasurface can be adjusted to operate at multiple frequencies.
APPLIED PHYSICS LETTERS
(2023)
