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Acoustic analysis of a flute-like silencer J. Sound Vib. (IF 3.429) Pub Date : 2021-02-23 Xiaochen Zhao; Hao Tan; Shang Li
The passive control of low-frequency duct noise remains a technical challenge. Herschel-Quincke (HQ) tube is effective in low frequency noise reflection. Previous studies showed that, when the bypass of the HQ tube is filled with a lighter gas and covered by tensioned membranes, the HQ tube becomes a flute-like silencer [L.Huang, Attenuation of low frequency duct noise by a flute-like silencer, Journal
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Gaussian Orthogonal Ensemble modeling of built-up systems containing general diffuse components and parametric uncertainty J. Sound Vib. (IF 3.429) Pub Date : 2021-02-22 Cédric Van hoorickx; Edwin P.B. Reynders
Built-up vibro-acoustic systems may contain components whose vibration field is sensitive to uncertainty from small spatial variations in geometry, material properties, or boundary conditions, which have a wave scattering effect. Such components can be modeled as diffuse. Statistical energy analysis (SEA) and related approaches are frequently employed for analyzing built-up systems with diffuse components
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A complete set of design rules for a vibro-impact NES based on a multiple scales approximation of a nonlinear mode J. Sound Vib. (IF 3.429) Pub Date : 2021-02-22 B. Youssef; R.I. Leine
The aim of the paper is to formulate a complete set of design rules for a vibro-impact nonlinear energy sink (VI NES). Hereto, analytical and numerical methods to extract the backbone curve of vibro-impact systems are presented. The adopted approach exploits the multiple scales method and is applied to a linear oscillator coupled with a VI NES. The dynamics of the system are explored and the system’s
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Enhanced modal matching method for macro- and micro-perforated plates J. Sound Vib. (IF 3.429) Pub Date : 2021-02-22 Cédric Maury; Teresa Bravo
Theoretical, numerical and experimental results are presented on the reactive and dissipative properties of backed or unbacked multilayer partitions made up of macro- or micro-perforated rigid panels in linear regime. The objective is to provide an enhanced multi-modal (EMM) formulation that accounts for high-order modes within the panel holes as well as visco-thermal boundary layers (VTBLs) over the
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Modal Analysis of Post-buckled Beams Undergoing Stable Transitions between Remote Equilibria J. Sound Vib. (IF 3.429) Pub Date : 2021-02-21 Haning Xiu; R. Benjamin Davis
Post-buckled structures are prone to snap-through instabilities when external loading causes the structure to lose local stability and jump to a remote equilibrium. However, using piezoelectric actuation, structures can undergo entirely stable transitions between remote equilibria, thereby avoiding snap-through. This paper investigates the linearized vibrational properties of post-buckled beams along
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Robust Sparse Representation Model for Blade Tip Timing J. Sound Vib. (IF 3.429) Pub Date : 2021-02-20 Zeng-Kun Wang; Zhi-Bo Yang; Hao-Qi Li; Shu-Ming Wu; Shao-Hua Tian; Xue-Feng Chen
Blade tip timing (BTT) is one of the most important non-contact monitoring methods for blade vibration estimation. BTT predominantly consists of two steps: 1) acquiring the original pulse signal generated by the rotating blade through optical probes. 2) Obtaining the arrival time of the original pulses through a high-precision counter and then transforming it to deflection. Multiple noise is involved
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Application of modal expansion method for sound prediction in enclosed spaces subjected to boundary excitation J. Sound Vib. (IF 3.429) Pub Date : 2021-02-19 Mirosław Meissner
In this paper, the steady-state and transient sound fields inside 3D enclosed spaces were examined theoretically using the modal expansion method. An analytic formula for the Green’s function was derived allowing to predict the interior sound field for both the harmonic and impulse boundary excitations. A theoretical model was tested numerically for a 3D car-like cavity with a sound absorbing material
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A versatile offset operator for the discrete observation of objects J. Sound Vib. (IF 3.429) Pub Date : 2021-02-13 Sergio De Rosa; Francesco Franco; Giuseppe Petrone; Alessandro Casaburo; Francesco Marulo
The possibility of reconstructing the response of a system, starting from the response of a reference one, has always been a point of great interest in structural dynamics. This is proved by the increasing attention about the similitude and scaling methods, although the associated predictions are still not fully reliable. Therefore, the aim of this paper is to present a method aimed at defining a transformation
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Extended Empirical Wavelet Transformation: Application to Structural Updating J. Sound Vib. (IF 3.429) Pub Date : 2021-02-12 Ali Karimpour; Salam Rahmatalla
The determination of accurate global and local modal information is a crucial step for any structural model updating process. Existing modal extraction methods can extract global modal properties with a good degree of accuracy; however, they have difficulties extracting accurate local information under transient excitations. This work presents a novel method, called Extended Empirical Wavelet Transformation
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Study of modal parameter estimation of time-varying mechanical system in time-frequency domain based on output-only method J. Sound Vib. (IF 3.429) Pub Date : 2021-02-08 Yan-song Wang; Lin Yang; Si-da Zhou; Lei Wei; Zi-qiang Hu
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Stability and Transient Analyses of Asymmetric rotors on anisotropic supports J. Sound Vib. (IF 3.429) Pub Date : 2021-02-10 Matteo Filippi; Erasmo Carrera; Politecnico di Torino
This paper makes use of high-order finite beam elements to perform stability evaluations and transient analyses of asymmetric rotors on anisotropic supports. Periodically time-varying motion equations are derived in the co-rotating reference frame, and they include all effects due to the rotational speed and angular acceleration. The periodic system stability is evaluated through the analysis of the
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Multiple zero-group velocity resonances in elastic layered structures J. Sound Vib. (IF 3.429) Pub Date : 2021-02-10 E.V. Glushkov; N.V. Glushkova
To date, the phenomenon of zero group velocity (ZGV) Lamb wave in a stress-free elastic plate has been well studied and used in non-destructive material characterization, electroacoustic devices and some other applications. This phenomenon is associated with the backward mode appearing in the range limited by the ZGV and cutoff frequencies. The modal frequency response of the structure, primarily the
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Nonlinear flutter of tapered and skewed cantilevered plates with curvilinear fiber paths J. Sound Vib. (IF 3.429) Pub Date : 2021-02-13 Mohammad Rahmanian; Touraj Farsadi; Hasan Kurtaran
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Locally-enriched procedure to simulate acoustic wave propagation in discontinuous media J. Sound Vib. (IF 3.429) Pub Date : 2021-02-19 Delfim Soares; Luis Godinho; Daniel Dias-da-Costa
In this paper, a highly straightforward approach is presented to simulate acoustic wave propagation in the presence of barriers. This formulation is particularly suited to tackle practical problems requiring the maximisation of noise loss by the optimal location of barriers, since the standard finite element approach has a significant computational burden from remeshing. The discontinuity-enriched
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Vibration Reduction by Stiffness Modulation – a Theoretical Study J. Sound Vib. (IF 3.429) Pub Date : 2021-02-19 Alexander Nowak; L. Flavio Campanile; Alexander Hasse
Semi-active vibration reduction techniques are defined as techniques in which controlled actions do not operate directly on the system’s degrees of freedom (as in the case of active vibration control) but on the system’s parameters, i.e., mass, damping, or stiffness. Cyclic variations in the stiffness of a structural system have been addressed in several previous studies as an effective semi-active
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Reduced order modeling of blades with geometric nonlinearities and contact interactions J. Sound Vib. (IF 3.429) Pub Date : 2021-02-19 E. Delhez; F. Nyssen; J.-C. Golinval; A. Batailly
This article presents a methodology dedicated to the vibration analysis of turbomachine blades accounting for both geometric nonlinearities and nonlinear blade-tip/casing contacts in a numerically efficient way through the use of reduced order models. Contact is numerically handled with Lagrange multipliers and the equation of motion is integrated forward in time using an explicit central difference
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Tunable electromagnetic resonant shunt using pulse-width modulation J. Sound Vib. (IF 3.429) Pub Date : 2021-02-09 Michel Auleley; Christophe Giraud-Audine; Hervé Mahé; Olivier Thomas
This article proposes a novel mean for tuning the natural frequency of an electromagnetic resonant shunt, using a pulse-width modulation (PWM) circuit. It is used to modulate the value of the capacitance of the shunt, and the electrical frequency is shown to be proportional to the command parameter of the PWM, the duty cycle. An easy and efficient strategy to tune the resonant shunt in real time is
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Ideal tooth profile modifications for improving nonlinear dynamic response of planetary gear trains J. Sound Vib. (IF 3.429) Pub Date : 2021-02-03 Veysel Yalın Öztürk; Ender Cigeroglu; H. Nevzat Özgüven
The ultimate goal in this study is to investigate the effects of tooth profile modifications (TPMs) on PGTs by performing parametric studies. For this purpose, firstly a nonlinear planetary gear dynamics model with time-varying stiffness is introduced. A time-varying stiffness function is included into the analysis by using loaded static transmission error (LSTE) for sun-planet and ring-planet gear
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A vibration absorber based on two-dimensional acoustic black holes J. Sound Vib. (IF 3.429) Pub Date : 2021-02-09 Hongli Ji; Ning Wang; Chao Zhang; Xiaodong Wang; Li Cheng; Jinhao Qiu
As a passive damping technique for vibration and noise mitigation, acoustic black hole (ABH) structures have been drawing an increasing attention because of their easy-to-realize and broadband wave focusing and energy dissipation characteristics. Structures with embedded ABHs, however, inevitably compromise the overall structural stiffness and strength, which hampers their use as critical structural
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Experimental and numerical investigation of energy harvesting from double cantilever beams with internal resonance J. Sound Vib. (IF 3.429) Pub Date : 2021-02-10 Reza Eshtehardiha; Reza Tikani; Saeed Ziaei-Rad
Conventional harvester systems usually have linear behavior. One of the great matters in these systems is that energy is harvested in a low frequency bandwidth. In this study, double cantilever beams connected at the end through a linear spring are used for energy harvesting. The bimorph piezoelectric patches are attached to the top beam by using double-sided tapes for energy harvesting. A pair of
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A generalized minimax-concave penalty based compressive beamforming method for acoustic source identification J. Sound Vib. (IF 3.429) Pub Date : 2021-02-08 Shilin Sun; Tianyang Wang; Fulei Chu
Acoustic source identification using compressive beamforming has been extensively investigated and applied in numerous fields. In this paper, a generalized minimax-concave (GMC) penalty based compressive beamforming method is proposed. The method solves acoustic inverse problems using the GMC penalty, by which the capacity of sound field reconstruction in low-frequency and low-signal-to-noise ratio
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Design of acoustic Fresnel zone plate for contact stress measurement of aero-engine rotor mating surface J. Sound Vib. (IF 3.429) Pub Date : 2021-02-18 Enxiao Liu; Yongmeng Liu; Xiaoming Wang; Junjie Zhi; Yuanlin Chen; Chuanzhi Sun; Jiubin Tan
Accurate measurement of the contact stress on the mating surface of the core engine's multi-stage rotor is of great significance for improving the structural connection quality and comprehensive performance of aero-engines. The phase reversal Fresnel zone plate (PR-FZP) can realize the focusing of ultrasonic wave and its focusing ability has an important influence on the measurement accuracy of contact
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Prediction of Fan Acoustic Blockage on Fan/Outlet Guide Vane Broadband Interaction Noise Using Efficient Frequency Domain Linearised Navier-Stokes Solvers J. Sound Vib. (IF 3.429) Pub Date : 2021-02-18 Ricardo Blázquez; Roque Corral
Fan/Outlet-Guide-Vane (OGV) interaction is a major broadband noise source in high bypass ratio turbofan engines. This paper assesses the acoustic shielding created by the fan rotor on the broadband noise generated by the interaction between the fan and the OGV. With this objective in mind, an efficient methodology to account for broadband noise transmission through a fan rotor using two-dimensional
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Merging Bragg and Local Resonance Bandgaps in Perforated Elastic Metamaterials with Embedded Spiral Holes J. Sound Vib. (IF 3.429) Pub Date : 2021-02-18 Xiangyu Tian; Wenjiong Chen; Renjing Gao; Shutian Liu
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Semi-active vibration control unit tuned to maximise electric power dissipation J. Sound Vib. (IF 3.429) Pub Date : 2021-02-03 Paolo Gardonio; Emanuele Turco; Aleksander Kras; Loris Dal Bo; Daniel Casagrande
This paper proposes a local approach for the on-line tuning of a semi-active vibration control unit, which is set to reduce the resonant response of target low-order flexural modes of distributed structures subject to broadband stochastic disturbances. The idea is to have multiple self-contained units, which can be fixed on thin walled structures to reduce flexural vibration and sound radiation at
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Ultra-wide low-frequency band gap in a tapered phononic beam J. Sound Vib. (IF 3.429) Pub Date : 2021-01-24 Seongmin Park; Wonju Jeon
We propose a tapered phononic beam with a broad low-frequency band gap for flexural waves. A unit cell of the phononic beam consists of two identical uniform parts and a thickness- and width-varying part sandwiched between them. Thickness and width profiles and uniform beam length are controlled to change the shear and rotational stiffnesses of the phononic beam, changing the starting and ending frequencies
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Underwater Acoustic Source Positioning by Isotropic and Vector Hydrophone Combination J. Sound Vib. (IF 3.429) Pub Date : 2021-02-17 V. Kavoosi; M.J. Dehghani; R. Javidan
Acoustic vector hydrophones are well-known for their ability in estimating the direction of arrival (DOA) of incoming signals. Moreover, despite its directivity, a vector hydrophone is capable of providing information about the received signal strength (RSS), just as an isotropic hydrophone. In this paper, a heterogeneous positioning system consisting of an isotropic and a vector hydrophone is considered
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Energy harvesting using a novel autoparametric pendulum absorber-harvester J. Sound Vib. (IF 3.429) Pub Date : 2021-02-09 Ao Zhang; Vladislav Sorokin; He Li
Autoparametric pendulum absorbers can transmit vibrational energy from the hosting structure to the motion of the pendulum and are effective if properly tuned. The motion of the pendulum can be also used to produce electrical power which can be harvested as renewable energy. This paper focuses on a novel configuration of the pendulum absorber-harvester that allows to improve its vibration suppression
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Sound transmission of acoustic metamaterial beams with periodic inertial amplification mechanisms J. Sound Vib. (IF 3.429) Pub Date : 2021-02-09 Yongzhen Mi; Xiang Yu
This paper presents the improved sound insulation performance obtained from a new type of acoustic metamaterial, built by attaching periodic inertial amplification (IA) mechanisms to a host beam. The IA mechanism is a triangular bar-and-hinge device, which connects a small mass to the host beam at two separate locations. The band structure of a unit-cell and the Sound Transmission Loss (STL) of a finite-length
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Nonlinear cyclic reduction for the analysis of mistuned cyclic systems J. Sound Vib. (IF 3.429) Pub Date : 2021-02-03 Samuel Quaegebeur; Benjamin Chouvion; Fabrice Thouverez
Predicting the vibratory response of bladed-disks in turbomachinery is of the utmost importance to design a reliable and optimized engine. Yet, such simulations are challenging mainly due to the large size of the finite-element model used to describe the system, the existence of random mistuning created by manufacture tolerances, and the nonlinear effects arising from the different components and their
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A combined acoustic and dynamic model of a defective ball bearing J. Sound Vib. (IF 3.429) Pub Date : 2021-02-15 Jing Liu; Yajun Xu; Guang Pan
Due to their special characteristics, angular contact ball bearings (ACBBs) are broadly applied in various mechancial systems. The working performance of rotating machinery can be determined by the internal ACBBs. Vibration and acoustic characteristics of ACCBs in various rotating machinery are becoming increasingly significant for the high-performance mechanical systems. An in-depth recognition of
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A time domain approach for shock noise prediction with decomposition analyses of large-scale coherent turbulent structures in jets J. Sound Vib. (IF 3.429) Pub Date : 2021-02-01 Weiqi Shen; Trushant K. Patel; Steven A.E. Miller
Broadband shock-associated noise (BBSAN) is one dominant component from off-design supersonic jets. A time-domain BBSAN model is proposed and evaluated, which is based on the vector Green’s function solution of the decomposed Navier–Stokes equations. The source term is the scalar product of the anisotropic velocities with the mean pressure gradient. The approach uses large-eddy simulation (LES) databases
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Nonlinear vibrations of beams with bilinear hysteresis at supports: interpretation of experimental results J. Sound Vib. (IF 3.429) Pub Date : 2021-02-02 Prabakaran Balasubramanian; Giulio Franchini; Giovanni Ferrari; Brian Painter; Kostas Karazis; Marco Amabili
Experimental vibration responses of beams with nonlinear boundary conditions were interpreted using a bilinear spring model. Two systems of beams were considered: one is a single rod and the second one is a cluster of parallel rods linked together. The boundary conditions at the beam ends, for both systems, were provided by spacer grids, which are specific supports used in nuclear industry. The experiments
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Mitigation of the aerodynamic noise of small axial wind turbines - methods and experimental validation J. Sound Vib. (IF 3.429) Pub Date : 2021-02-14 Kevin Volkmer; Nicholas Kaufmann; Thomas H. Carolus
Although the characteristic Reynolds number of small horizontal axis wind turbines is only in the order of 100,000, their noise emissions can be annoying. Three different modifications of the blades aiming at attenuating the aerodynamic noise mechanisms are investigated: (i) Optimization of the blade profile, (ii) application of boundary layer tripping and (iii) addition of serrations to the trailing
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Estimation of mechanical parameters based on output-only measurements using Kronecker product equivalence and mass perturbations J. Sound Vib. (IF 3.429) Pub Date : 2021-02-14 Max Vollmering; Maximilian Breitkreuz; Armin Lenzen
In this article the estimation of mechanical parameters using vibrational output-only measurements due to ambient excitations is elaborated. The estimated mechanical parameters are solely based on measurements. They are equivalent to analytically derived mechanical parameters of models, which are discretized corresponding to the measurement set-up. In comparison to the analytically derived models no
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NEAR-ELIMINATION OF SMALL OSCILLATIONS OF ARTICULATED FLEXIBLE-ROBOT SYSTEMS J. Sound Vib. (IF 3.429) Pub Date : 2021-02-14 Ahmed A. Shabana; Ahmed E. Eldeeb; Zhengfeng Bai
This paper proposes a new hybrid actuation system for near-elimination of the small oscillations of articulated flexible-robot systems (AFRS). The hybrid actuation control forces are obtained by solving a fully-constrained inverse-dynamics (FCID) problem of relatively stiff robots experiencing small deformations, which lead to deterioration of their performance and precision. The FCID procedure is
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Active vibration control and stability analysis of a time-delay system subjected to friction-induced vibration J. Sound Vib. (IF 3.429) Pub Date : 2021-02-13 J-J. Sinou; B. Chomette
The use of active vibration control may induce a delay leading to detrimental degradation of the performance of active vibration control. This is particularly true in the case of mechanical systems subjected to friction-induced vibration and noise for which such time-delays can lead to the appearance of undesirable instability. Furthermore, conducting a stability analysis of time-delay systems and
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Vibroacoustic subtractive modeling using a reverse condensed transfer function approach J. Sound Vib. (IF 3.429) Pub Date : 2021-01-27 F. Dumortier; L. Maxit; V. Meyer
Substructuring methods are a very common and efficient way to solve complex vibroacoustic problems. The Condensed Transfer Function (CTF) approach is a substructuring method based on the concept of subsystem condensed transfer functions (corresponding to admittances or impedances) that allows assembling acoustical or mechanical subsystems coupled along lines or surfaces. For certain practical applications
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Nonlinear dynamic response of an L-shaped beam-mass piezoelectric energy harvester J. Sound Vib. (IF 3.429) Pub Date : 2021-02-03 Haisheng Li; Haixia Sun; Baoyong Song; Dong Zhang; Xinchun Shang; Donghuan Liu
Piezoelectric energy harvesters (PEHs) have been taken considerable attention in decades. To evaluate the performance of the harvester in large deformation and high electric field conditions, nonlinear effects (geometric, material and damping nonlinearities) should be involved in analyzing the characteristic of the harvesters. In this article, the unimorph L-shaped harvester is investigated and influence
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Support position optimization with minimum stiffness for plate structures including support mass J. Sound Vib. (IF 3.429) Pub Date : 2021-02-03 D. Wang; M.I. Friswell
The optimum position and minimum restraint stiffness of a flexible point support to raise a natural frequency of a thin bending plate is investigated, with the inclusion of the corresponding additional support mass. First the derivatives of the natural frequencies of the plate structure are derived with respect to the support movement using a finite element model. Second, the minimum support stiffness
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Near-field effects on the sound transmission and absorption of elastic micro-perforated plates in impedance tubes J. Sound Vib. (IF 3.429) Pub Date : 2021-02-03 Hyun-Sil Kim; Pyung-Sik Ma; Bong-Ki Kim; Sang-Ryul Kim; Seong-Hyun Lee
In this study, the effects of near-field waves on the sound absorption and insulation performance of elastic micro-perforated plates (MPPs) installed in impedance tubes are studied. The sound absorption coefficient and the sound transmission loss (STL) of MPPs are computed by solving structure-acoustic coupled equations, and the results are compared to those by the finite element method (FEM) to confirm
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Dynamics of a Rotor Shaft Driven by a Non-Ideal Source through a Universal Joint J. Sound Vib. (IF 3.429) Pub Date : 2021-02-01 Saurabh Kumar Bharti; Anubhab Sinha; Arun Kumar Samantaray; Ranjan Bhattacharyya
A rigid rotor system which is driven through a Universal joint (U-joint) and is mounted on weakly-damped flexible supports exhibits principal and combination type parametric instabilities at certain torque-speed combinations. In this article, the transient dynamics of such a non-linear system driven by a non-ideal source (a DC motor) is studied through numerical simulation of the bond graph model of
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A simple equivalent plate model for dynamic bending stiffness of three-layer sandwich panels with shearing core J. Sound Vib. (IF 3.429) Pub Date : 2021-02-11 U. Arasan; F. Marchetti; F. Chevillotte; L. Jaouen; D. Chronopoulos; E. Gourdon
Equivalent or condensed plate models are being used in various industries to reduce the computation time in finite element modelling. Out of the available equivalent plate models, the model developed by J.L.Guyader in 1978 exhibits high agreement with Lamb wave theory but it requires some time for implementation. Therefore, in this paper, a simple model is proposed to quickly compute the dynamic equivalent
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Acoustic modelling and analyses of geometrically complex systems with Micro-perforated panels J. Sound Vib. (IF 3.429) Pub Date : 2021-02-02 Xiaoqi Zhang; Li Cheng; Yang Liu; Jingtao Du
Modeling of vibro/acoustic systems with embedded acoustic components of complex geometries is a challenging task. In particular, the presence of irregular-shaped acoustic modules, which are usually treated by finite element (FE) method, increases system complexities and makes the use of existing sub-structuring modeling techniques cumbersome. To tackle the problem, an efficient three-dimensional sub-structuring
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Analytical and experimental studies on out-of-plane dynamic parametric instability of a circular arch under a vertical harmonic base excitation J. Sound Vib. (IF 3.429) Pub Date : 2021-02-08 Zilin Zhong; Airong Liu; Jiyang Fu; Yong-Lin Pi; Jian Deng; Zhongyang Xie
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Local nonlinear stores induce global modal interactions in the steady-state dynamics of a model airplane J. Sound Vib. (IF 3.429) Pub Date : 2021-02-08 Jon Dewitt E. Dalisay; Keegan J. Moore; Lawrence A. Bergman; Alexander F. Vakakis
Local nonlinear attachments can affect the global dynamics of their linear host structures through modal interactions. This was shown previously in experimental and computational studies of a model airplane with local nonlinear attachments at its wings, under impulsive forcing. Here we study nonlinear modal interactions in the model airplane subject to harmonic excitation. We consider the case of both
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Application of decoupled ARMA model to modal identification of linear time-varying system based on the ICA and assumption of “short-time linearly varying” J. Sound Vib. (IF 3.429) Pub Date : 2021-02-02 Tengfei Chen; Guoping Chen; Weiting Chen; Shuo Hou; Yuxuan Zheng; Huan He
A new approach for time-varying (TV) modal parameters identification is proposed in this research. In the identification process, the entire signal is divided into successive short time windows, where the structure response under white noise excitation is transformed into modal coordinates by the Independent Component Analysis (ICA) method. The decoupled time-varying Auto-Regressive Moving-Average
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Characterization and suppression of the hydrodynamic instability in the time domain for acoustic propagation in a lined flow duct J. Sound Vib. (IF 3.429) Pub Date : 2021-02-08 Yuanyuan Deng; Antoni Alomar; Didier Dragna; Marie-Annick Galland
The gradient term suppression (GTS) method for removing the hydrodynamic instability appearing in the time-domain solutions of the linearized Euler equations (LEE) along a lined flow duct is assessed. For this, the characterization of a convective instability in the time domain, with the aid of a complementary modal analysis, is first presented. The effect of the mesh size and spatial filtering on
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A quasi-3D dynamic model for free vibration analysis of rotating pre-twisted functionally graded blades J. Sound Vib. (IF 3.429) Pub Date : 2021-01-30 Yukun Chen; Guoyong Jin; Tiangui Ye; Mingfei Chen
This study provides a quasi-three-dimensional (quasi-3D) dynamic model for rotating pre-twisted functionally graded (FG) blades based on the three-dimensional elasticity shell theory and Carrera unified formulation. The material properties of the pre-twisted FG blades alter continuously in the direction of the thickness. The boundary conditions (clamped-end and free-edge) are realized by utilizing
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Two-Dimensional delayed resonator for entire vibration absorption J. Sound Vib. (IF 3.429) Pub Date : 2021-02-06 Zbyněk Šika; Tomáš Vyhlídal; Zdeněk Neusser
A one dimensional active vibration absorber with time delayed feedback known as delayed resonator proved to be well applicable for entire vibration absorption of mechanical structure at known excitation frequency. As the main and so far unique result, the delayed resonator concept is transferred from one dimensional to two dimensional vibration absorption. In the first step, an ideal two dimensional
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Piezoelectrically induced nonlinear resonances for dynamic morphing of lightweight panels J. Sound Vib. (IF 3.429) Pub Date : 2021-01-14 Andrea Arena; Walter Lacarbonara
A rich variety of resonance scenarios induced in thin elastic plates by periodic axial strains is investigated to describe the morphing capability of flexible, ultra-lightweight panels. The strain-induced excitation is provided by embedded piezoelectric strips actuated by time-varying voltages. The study deals with plates characterized by geometric and mechanical symmetry entailing cylindrical motions
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Resonance characteristics of stochastic dual Duffing oscillators with coupled APHC J. Sound Vib. (IF 3.429) Pub Date : 2021-01-30 Deli Wang; Haiqing Pei; Wei Xu; Jitao Yao; Jiarong Shi; Juergen Kurths
This paper is concerned with the resonance manifestation of a stochastically driven system consisting of dual Duffing oscillators with coupled active-passive hybrid control (APHC), i.e., time-delayed feedback control and viscoelastic damping. Analytic solutions are successively determined in both deterministic and stochastic modes. Based on our simulations in the deterministic mode, changes to the
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A two-level adaptive chirp mode decomposition method for the railway wheel flat detection under variable-speed conditions J. Sound Vib. (IF 3.429) Pub Date : 2021-01-22 Shiqian Chen; Kaiyun Wang; Chao Chang; Bo Xie; Wanming Zhai
Wheel flat, as a common defect of railway vehicles, can cause large impact forces on both the vehicle and infrastructure components and thus seriously hinder the vehicle running stability and safety. Considering the complex track irregularities and variable-speed conditions, the vehicle vibration responses often contain strong interference signal components and exhibit time-varying frequency contents
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Understanding the low frequency response of carbon nanotube thermoacoustic projectors J. Sound Vib. (IF 3.429) Pub Date : 2021-01-17 Prashant Kumar; Rammohan Sriramdas; Ali E. Aliev; John B. Blottman; Nathanael K. Mayo; Ray H. Baughman; Shashank Priya
Carbon nanotube sheets exhibiting extremely low heat capacity have enabled the development of thermoacoustic projectors (TAPs) for a wide range of frequencies (1- 106 Hz). The sound pressure level of carbon nanotube (CNT) based TAPs is proportional to the frequency, resulting in a reduced performance at low frequencies. Hence, there is a need to determine the governing parameters of TAPs that can be
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Sound radiation of the exhaust gas turbocharger as a function of the compressor inflow J. Sound Vib. (IF 3.429) Pub Date : 2021-01-21 Johannes Moritz; Stefan Becker
The use of exhaust gas turbochargers in modern engine concepts is essential to achieve high efficiencies, low fuel consumption, and low emissions. However, the high rotational speed, a wide range of compression ratios, and dynamic acceleration and deceleration processes cause both tonal and broadband sound radiation. Due to packaging constraints, the intake cycle is often characterized by deflections
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Jet-installation noise reduction with flow-permeable materials J. Sound Vib. (IF 3.429) Pub Date : 2021-01-22 Leandro Rego; Daniele Ragni; Francesco Avallone; Damiano Casalino; Riccardo Zamponi; Christophe Schram
This paper investigates the application of flow-permeable materials as a solution for reducing jet-installation noise. Experiments are carried out with a flat plate placed in the near field of a single-stream subsonic jet. The flat plate is modular and the solid surface near the trailing edge can be replaced with different flow-permeable inserts, such as a metal foam and a perforated plate structure
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The dynamic resonance under multiple flexible wheelset-rail interactions and its influence on rail corrugation for high-speed railway J. Sound Vib. (IF 3.429) Pub Date : 2021-01-21 Chaozhi Ma; Liang Gao; Tao Xin; Xiaopei Cai; Mahantesh M Nadakatti; Pu Wang
The wheel-rail dynamic resonance (W-RDR) under multi wheelset-rail nonlinear interactions in the mid-high frequency range is still unclear regarding wheelset flexibility, wave transmissions and reflections (W-TF) among each wheel-rail interaction. To clearly elucidate W-RDR and its induced modes, a double vehicle-track coupled dynamic model of multiple flexible wheelset-rail interactions is established
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Experimental study of thermo-acoustic wave modulation in a cracked plate J. Sound Vib. (IF 3.429) Pub Date : 2021-01-24 K. Dziedziech; A. Klepka; J. Roemer; L. Pieczonka
This paper presents a study on nonlinear elastic wave modulation due to an applied periodic thermal field. The experimental study is performed with a thermal analogy of the vibro-acoustic wave modulation (VAM) technique. The aim is to identify sources of nonlinear effects appearing in the response signal of a damaged structure. Assigning specific nonlinear effects to their corresponding sources is
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Validation of FEM models based on Carrera Unified Formulation for the parametric characterization of composite metamaterials J. Sound Vib. (IF 3.429) Pub Date : 2021-01-30 A.G. De Miguel; M. Cinefra; M. Filippi; A. Pagani; E. Carrera
This work focuses on the study of composite metamaterials to be employed as possible lightweight insulation systems for noise and vibrations. In particular, the dispersion relations are derived by applying the Bloch-Floquet theory to the unit cell of the periodic microstructure. Advanced beam finite elements based on Carrera Unified Formulation are here extended, for the first time, to the dynamic
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Component Replacement TPA: a transmissibility-based structural modification method for in-situ transfer path analysis J. Sound Vib. (IF 3.429) Pub Date : 2021-01-30 J.W.R. Meggitt; A.S. Elliott; A.T. Moorhouse; A. Jalibert; G. Franks
In-situ Transfer Path Analysis is a diagnostic method used to analyse the propagation of noise and vibration through complex built-up structures. Its defining feature is the invariant characterisation of an assembly’s active components (i.e. vibration sources) by their blocked forces. This invariant characterisation enables the downstream structural modification of an assembly without affecting the
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