Article
Engineering, Mechanical
N. Menga, F. Bottiglione, G. Carbone
Summary: The paper evaluates the effectiveness of nonlinear viscoelastic damping in controlling base-excited vibrations. It investigates the robustness of nonlinear base isolation performance in controlling system response to a wide set of possible excitation spectra, showing that tuned nonlinear RLRB provides loads isolation in a wider range of excitation spectra.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2021)
Article
Acoustics
Y. Y. Chen, W. Zhao, C. Y. Shen, Z. C. Qian
Summary: In this paper, a magnetic bistable nonlinear energy sink (BNES) is proposed for reducing the vibration response of structures. The BNES can achieve similar performance as a thoroughly in-tuned TMD system in idealized situations, and outperforms the linear TMD and the cubic NES in detuned conditions due to its broadband high internal resonance capability. The study demonstrates that the proposed BNES can be used as an efficient passive vibration absorber for structural seismic control.
SHOCK AND VIBRATION
(2021)
Article
Engineering, Civil
Wei Wang, Cheng Fang, Deyang Shen, Ruibin Zhang, Jiemin Ding, Honglei Wu
Summary: A novel self-centering bracing system using disc spring-based dampers was proposed in this study, with comprehensive experimental research conducted on six full-scale damper specimens. The study found that the fullness of the flag-shaped hysteresis in the brace is a critical factor affecting key structural performance, and decreasing the energy dissipation factor can eliminate residual deformation at the cost of increased peak deformation and floor acceleration responses.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Civil
Sheng Li, Hing-Ho Tsang, Nelson Lam
Summary: This article proposes the use of superelastic tendon restraint on a shear frame to balance the reduction of seismic force demand and the control of overturning risk. The effectiveness and applicability of the proposed model were demonstrated through the development of an analytical model for the rocking response, physical model testing, and shaker table testing.
EARTHQUAKE ENGINEERING & STRUCTURAL DYNAMICS
(2023)
Article
Mathematics, Applied
Adnan S. Saeed, Mohammad A. AL-Shudeifat, Wesley J. Cantwell, Alexander F. Vakakis
Summary: This study introduces a two-dimensional nonlinear energy sink (2DNES) that can robustly suppress seismic excitations in arbitrary directions on the plane. Through numerical optimization and testing with historic earthquakes, it demonstrates the effectiveness of the optimized 2D-NES in mitigating multi-directional seismic excitations.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2021)
Article
Geochemistry & Geophysics
Xiao Chen, Zhaoyun Zong, Yinghao Zuo
Summary: Young's modulus and the Poisson ratio are important parameters for shale reservoir identification and oil and gas detection. The broadband inversion approach combines seismic ultralow-frequency information with inversion results in the complex frequency domain, improving the stability, reliability, and resolution of the inversion. However, current amplitude variation with offset (AVO) inversions mostly rely on linear approximations, and there are few exact nonlinear or broadband inversion methods. We propose a new exact reflection coefficient equation based on the Zoeppritz equation for the inversion of Young's modulus, Poisson ratio, and density in the broadband complex domain. This method provides a theoretical basis for evaluating reservoir brittleness and compressibility, as well as a new approach for shale gas reservoir prediction and sweet spot identification. The accuracy and rationality of this method are validated using synthetic and field data examples.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2023)
Article
Construction & Building Technology
Jinliang Bian, Wanlin Cao, Hongying Dong, Jianwei Chen
Summary: A fabricated structure composed of a CFST frame and an HSF shear wall was proposed to improve the seismic performance of prefabricated frame structures. Through experimental and numerical analyses, it was found that the HSF shear wall significantly enhances the bearing capacity, initial stiffness, and energy dissipation capacity of the CFST frame. Different details of the HSF shear wall have a substantial impact on the seismic performance of the structure.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Shuangshuang Jin, Yu Xie, Mengyi Li, Jiulin Bai
Summary: A plastic design method for SPSW-RCF structures based on energy balance is proposed in this paper. The design parameters of SPSW and RC frame are determined by calculating the design lateral story shear forces using the energy balance principle. Nonlinear dynamic analysis and comparative study are conducted to obtain performance indicators under different structural parameters, while the SPSW-resisted story shear ratio is quantified.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Wongsa Wararuksajja, Jarun Srechai, Sutat Leelataviwat, Trirat Sungkamongkol, Suchart Limkatanyu
Summary: The presence of masonry walls affects the seismic response of structures significantly, and infill panels can enhance the overall lateral stiffness and strength of structures. This study presents a design method to prevent local shear failure of RC columns due to infill-frame interactions, based on local plastic mechanism analysis and simplified equations with finite element analysis. The proposed method effectively prevents local failure and promotes ductile behavior in structures with masonry walls.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Engineering, Civil
KyoungSub Park, Brandon Price, Chatchai Jiansinlapadamrong, Shih-Ho Chao
Summary: This study introduces an innovative double-HSS link configuration for use in eccentrically braced frames, providing increased rotational capacity, simplified connection details, and reduced welding requirements. Experimental and analytical results show that the double-HSS links can sustain larger plastic rotations and meet AISC 341's acceptance criterion for shear yielding links.
ENGINEERING STRUCTURES
(2021)
Article
Engineering, Civil
Xinyu Wang, Linlin Xie, Demin Zeng, Cantian Yang, Qianmin Liu
Summary: This study investigated the resilience-oriented retrofitting of RCFSWBs through isolation, focusing on the critical design parameter, the yield ratio of the isolation system. By analyzing two cases, engineering demand parameters (EDPs) affecting the resilient performance of RCFSWBs before retrofitting were identified.
Article
Engineering, Civil
A. Farahbakhshtooli, Anjan K. Bhowmick
Summary: A reliable macro model has been developed for steel plate shear walls with regularly spaced circular perforations, validated against experimental results. Time history analyses showed that perforated SPSW systems have slightly lower shear performance compared to solid ones. Sensitivity assessment indicated that an increase in hole diameter decreases column axial force demand, while maintaining bending moments, and increases interstorey drift ratio due to decreased stiffness and strength.
THIN-WALLED STRUCTURES
(2021)
Article
Engineering, Civil
Fernando Gomez, Gaston A. Fermandois, Billie F. Spencer Jr.
Summary: This paper proposes an approach for optimal design of nonlinear energy sinks in structures subjected to stochastic excitation. The strategy involves equivalent linearization at each time step to address the inherent nonlinearity. The method is evaluated through comparison with Monte Carlo simulations of representative examples and the influence of Gaussian assumption is studied.
ENGINEERING STRUCTURES
(2021)
Article
Geochemistry & Geophysics
Gareth S. O'Brien
Summary: Nonlinear wave propagation is studied in geophysical problems using a numerical method that considers the relationship between local interaction constants and macroscopic nonlinear coefficients, reproducing common features of nonlinear wave propagation. The method is validated through theoretical dispersion properties and numerical results, showing complexity in dynamic and static deformation with the inclusion of nonlinearity.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2021)
Article
Mechanics
Jiuk Shin, Jong-Su Jeon
Summary: This paper introduces a seismic retrofit strategy using prefabricated fiber-reinforced polymer materials to enhance the seismic performance of existing reinforced concrete columns. By varying confinement and stiffness-related parameters, retrofit parametric models were created and simulated under different seismic loading scenarios to determine critical retrofit parameters for maximizing effectiveness against various seismic hazard levels. The effectiveness of the retrofit system was evaluated based on energy-based seismic demands, leading to proposed threshold values of retrofit parameters for optimal seismic retrofit design schemes.
COMPOSITE STRUCTURES
(2022)
Article
Mechanics
Jian En Chen, Timo Theurich, Malte Krack, Themistoklis Sapsis, Lawrence A. Bergman, Alexander F. Vakakis
Summary: The dynamics of linear oscillators attached to hierarchical chains of strongly nonlinear oscillators are studied in this research. It is found that at low excitation levels, the system exhibits linear behavior, while at high excitation levels, the system enters a chaotic state with energy cascading across the nonlinear chain. Additionally, chaotic synchronization is observed.
Article
Mechanics
Jon Dewitt E. Dalisay, Lejie Liu, Melih Eriten, Lawrence A. Bergman, Alexander F. Vakakis
Summary: Soft materials are increasingly used in load-bearing applications, and accurate testing and modeling of their mechanical properties are necessary. This study introduces an efficient methodology to measure the nonlinear viscoelastic properties of soft materials and validates it experimentally on flexible polyurethane foams.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Engineering, Mechanical
Alireza Mojahed, Kosmas L. Tsakmakidis, Lawrence A. Bergman, Alexander F. Vakakis
Summary: The classical time-bandwidth limit suggests it is impossible to store broadband waves for long times. However, recent studies have shown that this limit may be surpassed in nonlinear systems. This research presents a structure that allows for energy-tunable control of nonlinear energy flow in the frequency domain, enabling the storage of broadband waves for long durations.
NONLINEAR DYNAMICS
(2022)
Article
Mechanics
Chongan Wang, Sameh Tawfick, Alexander F. Vakakis
Summary: This study investigates the shock mitigation effectiveness of a granular-solid interface. It shows that the mismatch in impedance between the steel granules and the PTFE intruders limits the propagation of impulsive energy, resulting in effective shock reduction.
INTERNATIONAL JOURNAL OF NON-LINEAR MECHANICS
(2022)
Article
Acoustics
Joshua R. Tempelman, Alireza Mojahed, Majdi Gzal, Kathryn H. Matlack, Oleg V. Gendelman, Lawrence A. Bergman, Alexander F. Vakakis
Summary: This work experimentally demonstrates the effectiveness of inter-modal targeted energy transfer (IMTET), which can achieve non-resonant rapid energy transfer from low-to-high frequency structural modes. By conducting vibro-impact experiments in a cantilever beam system, the validity of theoretical predictions is confirmed, and the diverse potential applications of IMTET in engineering practice are emphasized.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Multidisciplinary
Xiangle Cheng, D. Michael McFarland, Huancai Lu, Alexander F. Vakakis, Lawrence A. Bergman
Summary: An analytical approach is presented for localizing travelling and standing waves on a circular membrane using an interior, continuous, ring-type viscoelastic support. The results are expected to be useful in the design of mechanical and acoustic systems for energy localization.
APPLIED MATHEMATICAL MODELLING
(2022)
Article
Acoustics
Alireza Mojahed, Lawrence A. Bergman, Alexander F. Vakakis
Summary: This paper focuses on formulating the concept of bandwidth for a general class of passive oscillatory dynamical systems and proposes a new bandwidth definition based on the transient energy evolution. The new definition overcomes the limitations of previous definitions and is compatible with nonlinear dynamics. It allows for quantifying and studying the contributions of individual harmonics and targeted energy transfers to the bandwidth.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Acoustics
C. Wang, A. Mojahed, S. Tawfick, A. Vakakis
Summary: This work explores the acoustics of an infinite, one-dimensional, linear waveguide with a nonlinear gate, utilizing neural network simulators to study the nonlinear acoustics and global non-reciprocity of the waveguide. By training the neural networks with simulation data and comparing the results, predictive design of the waveguide's acoustic non-reciprocity response regions can be achieved effectively.
JOURNAL OF SOUND AND VIBRATION
(2022)
Article
Engineering, Mechanical
Mohammad A. Bukhari, Oumar R. Barry, Alexander F. Vakakis
Summary: This work investigates the nonlinear acoustics of a 1D discrete strongly nonlinear locally resonant metamaterial. Numerical investigations demonstrate the existence of different families of traveling breathers that depend on the coupling coefficient. The outcome indicates the presence of two energy-dependent nonlinear propagation zones and three complementary attenuation zones for the infinite lattice case.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Mathematics, Applied
Chongan Wang, Alexander F. Vakakis, Sameh Tawfick
Summary: In this study, non-reciprocal frequency conversion is investigated in a linear two-dimensional acoustic waveguide with a nonlinearly coupled oscillator gate. The efficacy and robustness of frequency conversion are validated through numerical simulations, and it is found that the frequency conversion induced by the nonlinear gate is sensitive to the excitation parameters and exhibits non-reciprocity in energy transfer.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Engineering, Civil
Majdi Gzal, Juan E. Carrion, Mohammad A. AL-Shudeifat, Billie F. Spencer, Joel P. Conte, Alexander F. Vakakis, Lawrence A. Bergman, Oleg Gendelman
Summary: This study investigates a new intermodal targeted energy transfer (IMTET) concept for rapid and purely passive seismic mitigation of a twenty-story steel structure. The concept is based on introducing local strong vibro-impact nonlinearities generated by contacts between floors and an auxiliary core structure to scatter seismic input energy. The results show that IMTET can effectively redistribute energy and enhance seismic performance without adding mass to the building.
ENGINEERING STRUCTURES
(2023)
Article
Acoustics
Ali Kanj, Alexander F. Vakakis, Sameh Tawfick
Summary: On-chip phononic circuits enable customized transmission of elastic waves and can couple with electronics and photonics for new signal manipulation capabilities. A reduced-order model is constructed to demonstrate the transmission switching mechanism in coupled drumhead-resonator waveguides, showing how thermoelastic buckling induces phase transition and localization of frequency passband modes.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Engineering, Mechanical
Ali Kanj, Paolo Ferrari, Arend M. van der Zande, Alexander F. Vakakis, Sameh Tawfick
Summary: Nonlinear micro-electro-mechanical systems (MEMS) resonators offer new opportunities in sensing and signal manipulation through frequency tuning and increased bandwidth. This study designs, fabricates, and investigates drumhead resonators with strongly nonlinear dynamics, developing a reduced order model (ROM) to accurately capture their response. The resonators exhibit electrostatically-mediated thermoelastic buckling, with a tunability factor of 2.4x and switching between stiffness and softness.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Physics, Fluids & Plasmas
Joshua R. Tempelman, Alexander F. Vakakis, Kathryn H. Matlack
Summary: This paper proposes a method for manipulating wave propagation in phononic lattices by utilizing local vibroimpact nonlinearities. It demonstrates the scattering of energy in the wave number domain and the transfer of energy from lower to higher optical bands. The study also explores the concept of nonresonant interband targeted energy transfer and establishes scaling relations with respect to energy. The nonlinear dynamics of the system and the physical interpretation of the energy transfer are analyzed using numerical continuation and nonlinear normal modes.
Article
Acoustics
Joshua R. Tempelman, Alexander F. Vakakis, Kathryn H. Matlack
Summary: In this work, the researchers demonstrate the interpretation of propagating topological waves in valley Hall lattices using the linear degenerate modal basis. They show that a small subset of closely spaced modes make up the topological waves, allowing for the construction of analytical reduced-order models. This is possible due to the sparse density of the modal spectrum inside the topological band gap. The researchers utilize this result to refine group velocity predictions of propagating topological waves by matching the modal spectrum to the supercell dispersion diagram. They also use the damped modal spectrum to characterize variations in wave group velocity in damped topological lattices and predict edge-to-bulk transitions. This work establishes a framework for accurately characterizing undamped and damped topological wave propagation using classical dynamics.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Sandip Chajjed, Mohammad Khalil, Dominique Poirel, Chris Pettit, Abhijit Sarkar
Summary: This paper reports the generalization of the Bayesian formulation of the flutter margin method, which improves the predictive performance by incorporating the joint prior of aeroelastic modal parameters. The improved algorithm reduces uncertainties in predicting flutter speed and can cut cost by reducing the number of flight tests.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Pascal Zeise, Bernhard Schweizer
Summary: Air ring bearings are an improved version of classical air bearings, providing better damping behavior and allowing operation above the linear threshold speed of instability. However, there is a risk of dangerous vibrations in certain rotor systems, which can be addressed by considering ring tilting effects.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Zbynek Sika, Jan Krivosej, Tomas Vyhlidal
Summary: This paper presents a novel design of a compact six degrees of freedom active vibration absorber with six identical eigenfrequencies. The objective is to completely suppress the vibration of a machine structure with six motion components. By utilizing a Stewart platform structure equipped with six active legs, a spatial unifrequency absorber with six identical eigenfrequencies is achieved. The design is optimized using a correction feedback and active delayed resonator feedback.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Kai Li, Yufeng Liu, Yuntong Dai, Yong Yu
Summary: This paper presents a novel light-powered self-oscillating liquid crystal elastomer (LCE) bow that can self-oscillate continuously and periodically under steady illumination. The dynamics of the LCE bow are theoretically investigated and numerical calculations predict its motion regimes. The suggested LCE bow offers potential advantages in terms of simple structure, customizable size, flexible regulation, and easy assembly.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Carmelo Rosario Vindigni, Giuseppe Mantegna, Calogero Orlando, Andrea Alaimo
Summary: In this study, a simple adaptive flutter suppression system is designed to increase the operative speed range of a wing-aileron aeroelastic plant. The system achieves almost strictly passivity by using a parallel feed-forward compensator implementation and the controller parameters are optimized using a population decline swarm optimization algorithm. Numerical simulations prove the effectiveness of the proposed simple adaptive flutter suppression architecture in different flight scenarios.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Nicco Ulbricht, Alain Boldini, Peng Zhang, Maurizio Porfiri
Summary: The quantification of fluid-structure interactions in marine structures is crucial for their design and optimization. In this study, an analytical solution for the free vibration of a bidirectional composite in contact with a fluid is proposed. By imposing continuity conditions and boundary conditions, the coupled fluid-structure problem is solved and applied to sandwich structures in naval construction, offering insights into the effects of water on mode shapes and through-the-thickness profiles of displacement and stress.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Shahram Hadian Jazi, Mostafa Hadian, Keivan Torabi
Summary: Non-uniformity and damage are the main focus in studying vibrations of beam elements. An exact closed-form explicit solution for the transverse displacement of a nonuniform multi-cracked beam is introduced using generalized functions and distributional derivative concepts. By introducing non-dimensional parameters, the motion equation and its closed-form solution are obtained based on four fundamental functions. The impact of crack count, location, intensity, and boundary conditions on natural frequency and mode shape is evaluated through numerical study.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Eugenio Tramacere, Marius Pakstys, Renato Galluzzi, Nicola Amati, Andrea Tonoli, Torbjoern A. Lembke
Summary: This paper proposes the experimental stabilization of electrodynamic maglev systems by means of passive components, providing key technological support for the Hyperloop concept of high-speed and sustainable transportation.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Pengfei Deng, Xing Tan, He Li
Summary: In this paper, the authors improve the surface morphology method and study the bit-rock interaction model between the rock and the PDC bit, taking into account the impact of blade shape and cutter arrangement. They establish a dynamic model for a deep drilling system equipped with an arbitrary shape PDC bit and propose a stability prediction method. The results show that the shape of the blades and arrangement of the cutters on the PDC bit significantly affect the nonlinear vibration of the drilling system.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Salvador Rodriguez-Blanco, Javier Gonzalez-Monge, Carlos Martel
Summary: In modern LPT designs, the simultaneous presence of forced response and flutter in different operation regimes is unavoidable. Recent evidence suggests that the traditional linear superposition method may be overly conservative. This study examines the flutter and forced response interaction in a realistic low pressure turbine rotor and confirms that the actual response is much smaller than that predicted by linear superposition.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Kabilan Baskaran, Nur Syafiqah Jamaluddin, Alper Celik, Djamel Rezgui, Mahdi Azarpeyvand
Summary: This study investigates the impact of the number of blades on the aeroacoustic characteristics and aerodynamic performance of propellers used in urban air mobility vehicles. The results show that different blade numbers exhibit distinct noise levels, providing valuable insights for further research on propeller noise and aerodynamic performance.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Yongbo Peng, Peifang Sun
Summary: This study focuses on the reliability-based design optimization (RBDO) of the tuned mass-damper-inerter (TMDI) system under non-stationary excitations. The performance of the optimized TMDI system is evaluated using probability density evolution analysis. The results demonstrate the technical advantages of TMDI, including high vibration mitigation performance, considerable mass reduction, and less stroke demand.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Guanfu Lin, Zhong-Rong Lu, Jike Liu, Li Wang
Summary: Vision-based measurement is an emerging method that enables full-field measurement with non-contact and high spatial resolution capabilities. This paper presents a single-camera method for measuring out-of-plane vibration of plate structures using motion-parametric homography to capture image variation and displacement response.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Bronislaw Czaplewski, Mateusz Bocian, John H. G. Macdonald
Summary: Despite two decades of study, there is currently no model that can quantitatively explain pedestrian-generated lateral forces. This research proposes a foot placement control law based on empirical data to calibrate and generalize the rigid-leg inverted pendulum model (IPM) for predicting lateral structural stability.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Justine Carpentier, Jean-Hugh Thomas, Charles Pezerat
Summary: This paper proposes an improved method for the identification of vibration sources on a car window using the corrected force analysis technique. By redefining inverse methods in polar coordinates, more accurate results can be obtained.
JOURNAL OF SOUND AND VIBRATION
(2024)
