Article
Materials Science, Multidisciplinary
Yi Zeng, Shu-Yan Zhang, Hong-Tao Zhou, Yan-Feng Wang, Liyun Cao, Yifan Zhu, Qiu-Jiao Du, Badreddine Assouar, Yue-Sheng Wang
Summary: This study introduces a seismic metamaterial consisting of inverted T-shaped structures with an ultra-wide first bandgap for strong attenuation of seismic waves. By analyzing complex band structures, it is found that the bandgap is divided into two parts with surface evanescent waves and no surface modes, affecting the propagation of seismic surface waves differently. The effectiveness of the ultra-wide bandgap is validated through large-scale field experiments with a two-dimensional version of the metamaterial.
MATERIALS & DESIGN
(2021)
Article
Materials Science, Multidisciplinary
Weijia Yu, Linyun Zhou
Summary: Elastic metamaterials (EMMs) have been extensively studied for their ability to control the propagation of elastic waves. However, the complex nonlinear behavior of soil poses challenges for implementing existing EMMs in practical engineering applications. To address this limitation, a seismic metamaterial surface (SMMS) is proposed for isolating Rayleigh waves over a wide frequency range. The SMMS design range is determined based on the propagation velocity of Rayleigh waves in EMMs, and a unit cell is constructed to demonstrate the desired material properties. Numerical results and scaled experiments confirm the efficacy of the new SMMS in reducing surface deformation by over 96%.
MATERIALS & DESIGN
(2023)
Article
Engineering, Mechanical
Hua-Yang Chen, Zhen-Hui Qin, Sheng-Nan Liang, Xin Li, Si-Yuan Yu, Yan-Feng Chen
Summary: A gradient-index seismic metamaterial based on a surface acoustic PnC is proposed to provide omnidirectional protection against ultra-broadband seismic Rayleigh waves.
EXTREME MECHANICS LETTERS
(2023)
Article
Physics, Applied
Angana Bhattacharya, Rakesh Sarkar, Ajinkya Punjal, Shriganesh S. S. Prabhu, Gagan Kumar
Summary: In this study, a toroidal excitation-based metamaterial was investigated, which can convert terahertz light from linear polarization state to orthogonal polarization state, achieving a polarization conversion of nearly 40% over a broad spectrum.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Chemistry, Physical
Sadeq Malakooti, Mohammad I. Hatamleh, Rui Zhang, Tahereh Taghvaee, Max Miller, Yao Ren, Ning Xiang, Dong Qian, Chariklia Sotiriou-Leventis, Nicholas Leventis, Hongbing Lu
Summary: The study reveals a mechanical metamaterial-like behavior in aliphatic polyurea aerogels based on their micro/nanostructure, showing broadband vibration mitigation at low frequencies. The negative dynamic material stiffness of the micro-metastructured aerogels is confirmed through simulations, covering a wider frequency range compared to previously reported locally resonant metamaterials.
Article
Engineering, Mechanical
Guobiao Hu, Andrew C. M. Austin, Vladislav Sorokin, Lihua Tang
Summary: This paper investigates a technique for broadband vibration suppression using a graded metamaterial beam, proposes a design strategy and defines three figures of merit to evaluate its performance. A parametric study reveals the effects of frequency spacing and damping ratio on the vibration suppression performance, and shows that by tuning these parameters, a significant increase in attenuation bandwidth can be achieved.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Engineering, Geological
Benchen Zhang, Hsuan Wen Huang, Farnyuh Menq, Jiaji Wang, Kalyana Babu Nakshatrala, K. H. Stokoe, Y. L. Mo
Summary: Both periodic barriers and periodic foundations can be used as passive isolation measures to reduce unfavorable vibrations affecting the protected superstructure. A series of field tests were conducted to evaluate the combined usage of periodic barriers and periodic foundations for better wave isolation effect. The results showed that the filtering capabilities of both barriers and foundations complement each other, contributing to mitigating vibrations in the protected superstructure.
SOIL DYNAMICS AND EARTHQUAKE ENGINEERING
(2022)
Article
Engineering, Mechanical
Xiang Fang, Jia Lou, Yu Mei Chen, Ji Wang, Ming Xu, Kuo-Chih Chuang
Summary: In this study, the concept of constructing inertant seismic metamaterials for Rayleigh wave attenuation using inerter-based vibration absorbers is proposed. Three typical oscillator configurations are considered in the design, controlled by an inertant mechanical network. An expanded effective medium method is developed to analyze the dispersion of Rayleigh waves and the influences of inertance-to-mass ratio and stiffness ratio on wave propagation are discussed. The results show that multiple-resonance IDVAs efficiently open low-frequency band gaps without increasing the mass of the resonators, and the addition of dissipative mechanisms further enhances Rayleigh wave attenuation.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Thermodynamics
Bao Zhao, Henrik R. Thomsen, Jacopo M. De Ponti, Emanuele Riva, Bart Van Damme, Andrea Bergamini, Eleni Chatzi, Andrea Colombi
Summary: This study proposes a graded metamaterial-based energy harvester for collecting energy from low-frequency ambient vibrations. By combining graded metamaterials, resonators, piezoelectric patches, and a self-powered interface circuit, broad-band and high-capability energy harvesting is achieved. The design is validated through theoretical modeling, numerical simulations, and experiments, showing a significant improvement in power collection performance compared to conventional harvesters.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Physics, Applied
Le Liu, Long-Xiang Xie, Weichun Huang, Xiu Juan Zhang, Ming-Hui Lu, Yan-Feng Chen
Summary: Sound absorption is crucial for room acoustics and noise control. Acoustic metamaterials, especially those based on deep learning, show promise in achieving broadband sound absorption. This letter presents a deep learning-based acoustic metamaterial approach that achieves ultra-broadband sound absorption without visible oscillation. Results from numerical simulations and experiments demonstrate the effectiveness and versatility of this approach.
APPLIED PHYSICS LETTERS
(2022)
Article
Engineering, Mechanical
Weifeng Jiang, Ming Yin, Qihao Liao, Luofeng Xie, Guofu Yin
Summary: This study introduces a class of 3D single-phase elastic metamaterials exhibiting both locally resonant and Bragg scattering bandgaps, which can overlap to form an ultra-wide vibration attenuation frequency range. The results are verified experimentally using additive manufacturing, suggesting a feasible approach for realizing elastic metamaterials for engineering application.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Engineering, Mechanical
Dunhui Yao, Maokun Xiong, Jinyu Luo, Lingyun Yao
Summary: This paper proposes a theoretical model of flexural wave bandgaps in locally resonant cylindrical curved shells and investigates a technique for broadband wave mitigation using metamaterial cylindrical curved shells. Utilizing periodic graded arrays technique can effectively broaden the frequency range of bandgaps.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Zongcheng Xu, Yujie Li, Bin Han, Quan Yuan, Yanan Li, Weiyan He, Junhua Hao, Liang Wu, Jianquan Yao
Summary: In this paper, a design of an ultra-broadband THz metamaterial absorber with high absorptivity is presented. Numerical simulations demonstrate that the proposed absorber achieves over 90% absorption in the frequency range of 0.62-8.75 THz, with an effective absorption bandwidth of 8.13 THz, when using undoped silicon with a conductivity of 600 S/m. The absorber exhibits strong absorption and wide bandwidth due to diffraction and impedance matching. Furthermore, it is polarization-insensitive and can operate over a wide range of incidence angles for TM terahertz waves.
RESULTS IN PHYSICS
(2023)
Article
Acoustics
Xuebin Zhang, Jun Zhang, Tao Liu, Ning Hu
Summary: This study proposes a tunable metamaterial beam to isolate flexural waves. A genetic algorithm-based size optimization is used to obtain a broad low-frequency bandgap. The tunability of the beam is achieved by attaching different numbers of permanent magnets to change the mass of the resonators. Additionally, ultra-broadband flexural wave attenuation is achieved by forming a gradient metamaterial beam based on the rainbow effect. Numerical and experimental results confirm the good flexural wave attenuation ability of the proposed beam.
Article
Physics, Multidisciplinary
Jingyi Yao, Ke Xu, Dunhui Yao, Lingyun Yao
Summary: This paper investigates the use of local resonators to achieve broadband longitudinal wave attenuation in a metamaterial cylindrical shell. Numerical models of the shell are established and the dispersion relation and vibration transmission characteristics are calculated. A multiple-graded-resonator metamaterial cylindrical shell is proposed to further broaden the bandgaps and the suppression range of longitudinal waves. Numerical and experimental results show good vibration suppression effects in the range of approximately 180-710 Hz.
FRONTIERS IN PHYSICS
(2023)
Article
Engineering, Civil
Danilo S. Kusanovic, Elnaz Seylabi, Domniki Asimaki
Summary: The study found that dynamic soil-structure interaction (SSI) is often neglected in the design of building structures, with many structures being analyzed using a rigid base assumption that ignores SSI. The NIST recommendations introduced a simplification for time-domain analysis, aiming to quantify the accuracy of this approach through numerical simulations and Bayesian methods.
EARTHQUAKE SPECTRA
(2021)
Article
Engineering, Geological
Mojtaba Salehi Dezfooli, Himan Hojat Jalali, Mohammad Razavi, Ali Abolmaali
Summary: A comprehensive parametric study using nonlinear finite-element analysis was conducted to predict the deformation and forces of buried large diameter steel pipes during construction. Equations were developed to estimate changes in pipe diameter and internal forces during construction, incorporating mechanical properties of various components and dimensions. These equations can serve as a tool for engineers to calculate desired outputs without the need for a sophisticated finite-element analysis program.
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2021)
Article
Engineering, Civil
Elnaz Seylabi, Mohamad M. Hallal, Brady R. Cox
Summary: This article applies a heterogeneous data assimilation technique to estimate compression and shear wave velocity, as well as damping at Treasure Island and Delaney Park. The joint inversion of earthquake acceleration time series and surface wave dispersion data improves the well-posedness of the inverse problem. The results show good agreement between the estimated profiles and measured profiles, and suggest that further improvements can be made by integrating additional information.
EARTHQUAKE SPECTRA
(2022)
Article
Geochemistry & Geophysics
Elif Ecem Bas, Elnaz Seylabi, Alan Yong, Hesam Tehrani, Domniki Asimaki
Summary: This study uses an ensemble Kalman method to improve the resolution and reduce uncertainties in seismic site characterization. The results suggest that a refined model provides better near-surface characteristics, while different models yield distinct P-wave velocity profiles with increasing uncertainty at deeper layers.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Construction & Building Technology
Maziar Fahimi Farzam, Himan Hojat Jalali
Summary: Tuned mass damper inerter (TMDI) is an effective device for mitigating structural vibrations. However, to overcome limitations caused by connecting to lower stories, a rooftop tandem tuned mass damper inerter (TTMDI) device is proposed. This device divides the mass of the TMDI into two variable masses and optimizes their parameters using particle swarm optimization algorithm. The results show that the rooftop TTMDI outperforms traditional TMDI configurations in terms of performance and robustness.
STRUCTURAL CONTROL & HEALTH MONITORING
(2022)
Article
Computer Science, Software Engineering
Danilo S. Kusanovic, Elnaz Seylabi, Domniki Asimaki
Summary: We introduce Seismo-VLAB (SVL), a new open-source, object-oriented finite element software designed to optimize meso-scale simulations in structural and geotechnical engineering. SVL includes state-of-the-art tools and parallel computing capabilities for efficient modeling of soil-structure interaction and wave propagation in heterogeneous half-spaces, such as perfectly matched layer, domain reduction method, dynamic nonlinear solvers, cutting edge parallel linear system solvers, domain decomposition method, and various plasticity models. This work presents the numerical implementation and software structure, allowing enthusiastic developers to contribute to this open-source project and showcases the software capabilities using an illustrative example.
Article
Computer Science, Interdisciplinary Applications
Fady A. Elshazly, Elnaz Seylabi
Summary: This study investigates the seismic behavior of soil- structure systems with a meta-foundation designed using alternate layers of concrete and rubber. The Floquet-Bloch theory was used to derive the frequency band gaps of the meta-foundation. A finite element simulation was proposed to study the isolation performance of meta-foundations on or embedded in soil. The results show considerably enhanced structural performance and improved soil response for the meta-foundation system compared to the non-isolated system.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Mathematics
Danilo S. Kusanovic, Elnaz E. Seylabi, Peyman Ayoubi, Kien T. Nguyen, Joaquin Garcia-Suarez, Albert R. Kottke, Domniki Asimaki
Summary: This article introduces Seismo-VLAB (SVL v1.0-stable), an open-source software designed for SSI simulations in the field of structural and geotechnical engineering. The software incorporates advanced techniques and parallel computing capabilities to address large-scale problems. The authors provide a detailed description of the implementation, validate some of SVL's features, and demonstrate its practical application in analyzing SSI and directionality effects under seismic loading.
Article
Construction & Building Technology
M. Amin Soltanianfard, Khaled Abuhishmeh, Himan Hojat Jalali, Surendra P. Shah
Summary: This study explores the feasibility of using wastewater as an alternative to potable water in concrete construction. The results show that concrete made with wastewater has comparable performance to that made with potable water. The study also reveals the correlation between wastewater filtration levels, hydration, and water absorption.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Computer Science, Interdisciplinary Applications
Kien T. Nguyen, Elnaz Seylabi, Domniki Asimaki
Summary: The study proposes a dual frequency-and deformation-dependent macroelement model to analyze the dynamic axial interaction between buried structures and soil. This approach utilizes Modified Bouc-Wen and Gyromass models for the development of the macroelement model. The results of the proposed method are in good agreement with published experiments and finite element analyses. It is found that neglecting frequency dependency can lead to an underestimation of axial strain.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Computer Science, Interdisciplinary Applications
Hamid Taghavi Ganji, Elnaz Seylabi
Summary: This paper presents a variant of LSTM recurrent neural network for modeling and predicting the seismic response of buried structures to uncertain shear waves in heterogeneous soil profiles. The proposed model can accept uncertain input features and uses synthetic time histories for training to improve efficiency. The results demonstrate that this approach can effectively predict tunnel response at different locations and show high accuracy in forward uncertainty quantification and sensitivity analysis.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Civil
Elnaz Seylabi, Doriam Restrepo, Ricardo Taborda, Domniki Asimaki
Summary: The study introduces a deterministic ground motion simulation approach that considers the cyclic multiaxial response of sediments in the shallow crust, using the Garner Valley in Southern California as a test case. The model's advantage lies in its minimal number of free parameters that need calibration, making it suitable for regional-scale simulations.
EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS
(2021)
