Showing papers in "Journal of Vibration and Control in 2015"
TL;DR: The utilization of structural control systems for alleviating the responses of civil engineering structures, under the effects of different kinds of dynamics loadings, has become a standar....
Abstract: Nowadays the utilization of structural control systems for alleviating the responses of civil engineering structures, under the effects of different kinds of dynamics loadings, has become a standar ...
190 citations
TL;DR: A new methodology for the chatter detection in computer numerical control milling machines is proposed, based on vibratory signal analysis and artificial intelligence, and tested on a milling machine at different depths of cut and various rotational speeds.
Abstract: In modern industry, milling is an important tool when a high material removal rate is required. Chatter detection in this situation is a crucial step for improving surface quality and reducing both noise and rapid wear of the cutting tool. This paper proposes a new methodology for the chatter detection in computer numerical control milling machines. This methodology is based on vibratory signal analysis and artificial intelligence. The methodology consists of five major steps: (1) data acquisition, (2) signal processing, (3) features generation, (4) features selection and (5) classification. As chatter components occur around system resonance frequencies, a multiband resonance filtering method is proposed at the processing step. The process is then followed by envelope analysis. This allows the signal-to-noise ratio to be increased and the sensitivity of generated features to be increased. Extracted features are then ranked based on their entropy in which only best features are selected and presented to t...
95 citations
TL;DR: In this paper, the authors proposed permutation entropy as a tool to select best wavelet for feature selection for the detection as well as fault classification of ball bearings, the continuous wavelet coefficients of the time domain signal are calculated at real, positive scales using various real and complex wavelets.
Abstract: The detection and diagnosis of bearing health status using vibration signal has been an important subject for extensive research over the past few decades. The objective of this paper is to proposed permutation entropy as a tool to select best wavelet for feature selection for the detection as well as fault classification of ball bearings. The continuous wavelet coefficients of the time domain signal are calculated at real, positive scales using various real and complex wavelets. Best wavelet and corresponding scale is selected based on minimum permutation entropy. Eleven statistical parameters were used for defect classification in outer race, inner race, ball defect and healthy bearing respectively. Proposed methodology for fault classification is compared with two artificial intelligence techniques such as artificial neural network and support vector machine. Results revealed that permutation entropy based feature extraction techniques provide higher classification accuracy even when there is a slight ...
94 citations
TL;DR: In this paper, a bearing fault diagnosis method has been proposed based on multi-scale permutation entropy (MPE) and adaptive neuro fuzzy classifier (ANFC), which is applied for feature extraction to reduce the complexity of feature vector.
Abstract: The rolling element bearing is among the most frequently encountered component in a rotating machine. Bearing fault can cause machinery breakdown and lead to productivity loss. A bearing fault diagnosis method has been proposed based on multi-scale permutation entropy (MPE) and adaptive neuro fuzzy classifier (ANFC). In this paper, MPE is applied for feature extraction to reduce the complexity of the feature vector. Extracted features are given input to the ANFC for an automated fault diagnosis procedure. Vibration signals are captured for healthy and faulty bearings. Experiment results pointed out that proposed method is a reliable approach for automated fault diagnosis. Thus, this approach has potential in diagnosis of incipient bearing faults.
90 citations
TL;DR: In this article, a new mathematical model, named the equivalent fractional Kelvin model, which considers temperature and frequency effects simultaneously, is proposed to clarify the mechanical properties of VE dampers, and the numerical results using this model are in good agreement with experimental results.
Abstract: In this paper, tests on viscoelastic (VE) dampers are carried out, and the results indicate that VE dampers have high energy dissipation capacity and excellent anti-fatigue properties. To clarify the mechanical properties of VE dampers, a new mathematical model, named the equivalent fractional Kelvin model, which considers temperature and frequency effects simultaneously, is proposed. The numerical results using this model are in good agreement with experimental results. Then, through analysis on a five-story reinforced concrete frame structure with and without VE dampers, it is found that the seismic responses of the structure with VE dampers are significantly reduced and VE dampers have high energy dissipation capacity.
75 citations
TL;DR: In this paper, a tuned liquid damper (TLD) consisting of two-layer hemispherical containers, partially filled with water, was investigated as a cost-effective method to reduce the wind-induced vibration of a wind generator.
Abstract: A tuned liquid damper (TLD), which consisted of two-layer hemispherical containers, partially filled with water, was investigated as a cost-effective method to reduce the wind-induced vibration of ...
57 citations
TL;DR: In this paper, the authors presented an analytical investigation on the nonlinear dynamic analysis of functionally graded double curved thin shallow shells using a simple power-law distribution with temperature-dependent properties on an elastic foundation and subjected to mechanical load and temperature.
Abstract: This paper presents an analytical investigation on the nonlinear dynamic analysis of functionally graded double curved thin shallow shells using a simple power-law distribution (P-FGM) with temperature-dependent properties on an elastic foundation and subjected to mechanical load and temperature. The formulations are based on the classical shell theory, taking into account geometrical nonlinearity, initial geometrical imperfection, temperature-dependent properties and unlike other publications, Poisson ratio is assumed to be varied smoothly along the thickness ν=ν(z). The nonlinear equations are solved by the Bubnov-Galerkin and Runge-Kutta methods. The obtained results show the effects of temperature, material and geometrical properties, imperfection and elastic foundation on the nonlinear vibration and nonlinear dynamical response of double curved FGM shallow shells. Some results were compared with those of other authors.
56 citations
TL;DR: In this paper, the authors used the genetic algorithm (GA) to optimize the tool wear rate parameters and validated the practical significance of applying GA to tool wear rates by computing the deviation between predicted and experimentally obtained process parameters.
Abstract: Numerous developments have been witnessing in manufacturing industries the ability of the machines to change the tools automatically during their wear or damage. In general, tool failure contributes about 7% to the down time of machine centers. Therefore, online monitoring of tool wear is an important phenomenon in producing quality products at reasonable cost. This also increases the production rate in the industries. Tool condition monitoring using the acoustic emission technique (AET) are real methods identified by researchers for online quality assessment of machine tools. The genetic algorithm (GA) is used to optimize the tool wear rate parameters. The practical significance of applying GA to tool wear rate has been validated by means of computing the deviation between predicted and experimentally obtained process parameters. Based on this research work, an experimental setup has been developed for online monitoring of a single point cutting tool using AETs. The experimental tool wear rate results ar...
55 citations
TL;DR: In this article, the accumulative amplitudes of carrier orders and energy ratio based on difference spectra are proposed for monitoring and diagnosing planetary gearboxes, and the effectiveness of the proposed features is demonstrated using the vibration data acquired from a planetary gearbox test rig.
Abstract: Planetary gearboxes are widely used in aerospace, automotive and heavy industrial applications that require compactness and high torque-to-weight ratios. Despite these advantages, tough operation conditions under which planetary gearboxes are typically used may lead to damage on their key components, for example, gears and bearings. Because of the unique behaviors of planetary gearboxes significantly different from fixed-axis gearboxes, the diagnostic features developed and working well for fixed-axis gearboxes will degrade when applied to planetary gearboxes. Therefore, there is a demand to develop features specifically for monitoring and diagnosing planetary gearboxes. To meet this demand, this paper proposes two features, namely, accumulative amplitudes of carrier orders and energy ratio based on difference spectra. The effectiveness of the proposed features is demonstrated using the vibration data acquired from a planetary gearbox test rig. The vibration data is measured under different motor speeds a...
54 citations
TL;DR: In this paper, the theoretical and simulation analyses have been studied to prove the effectiveness of the pounding tuned mass damper (PTMD) to control the vibration of a traffic load.
Abstract: In the first part of this paper, the theoretical and simulation analyses have been studied to prove the effectiveness of the pounding tuned mass damper (PTMD) to control the vibration of a traffic ...
51 citations
TL;DR: In this article, an active vibration control (AVC) method achieving the minimum vibration force and torque within a desired vibration displacement is presented in an active magnetic bearing (AMB) system.
Abstract: Rotor imbalance causes undesirable synchronous vibrations of displacement, force and torque. An active vibration control (AVC) method achieving the minimum vibration force and torque within a desired vibration displacement is presented in an active magnetic bearing (AMB) system. First, the dynamics of the AMB system with static imbalance and dynamic imbalance are introduced, and the dimensional displacement relationships of the rotation, geometric and inertial axes of the rotor are described. Demands of the AVC are analyzed, and the results indicate that the rotation axis has to be controlled to move along the center line and the inclination direction of the geometric axis and the inertial axis, respectively. Then the synchronous vibration displacement is identified with a general notch filter, and a feedforward controller is designed to control the rotation axis by providing a synchronous control current. A gain phase modifier (GPM) is proposed to achieve a precise synchronous control current and to comp...
TL;DR: In this article, the fractional order of a new chaotic system was studied and the minimum effective dimension for which the system remains chaotic was calculated, and the chaos synchronization of two identical and non-identical fractional orders of the new system by using active control was presented.
Abstract: In this paper, the fractional order of a new chaotic system was studied and the minimum effective dimension for which the system remains chaotic was calculated. We have presented the chaos synchronization of two identical and nonidentical fractional orders of the new system by using active control. Furthermore, the Laplace transform and the Niemann–Trouvaille fractional integral operator were used for synchronizing two system.
TL;DR: In this paper, a sliding mode control for a class of fractional uncertain chaotic systems under perturbations of parameters is proposed, where a fractional integral sliding surface is proposed.
Abstract: This paper deals with a sliding mode control for a class of fractional uncertain chaotic systems under perturbations of parameters. A fractional integral sliding surface is proposed for fractional-...
TL;DR: In this paper, a dynamic vibration absorber (DVA) is used as an effective vibration control device, which is essentially a secondary mass, attached to an original system via a spring and damper.
Abstract: A dynamic vibration absorber (DVA) can be used as an effective vibration control device. It is essentially a secondary mass, attached to an original system via a spring and damper. The natural freq...
TL;DR: In this paper, the authors deal with parameter identification for basic and generalized Kelvin-Voigt and Maxwell models for fluid viscous dampers, and the identification procedure gives the best mechanical parameters by minimizing a suitable objective function that represents a measure of difference between analytical and experimental applied forces.
Abstract: Fluid viscous dampers have been widely applied to reduce the effects of vibrations in civil engineering structures. A good understanding of the dynamical behavior of these devices is required to analyze structures equipped with fluid viscous dampers. The simple Kelvin–Voigt and Maxwell rheological models do not have enough parameters to suitably capture the frequency dependence of device parameters, so other models representing some generalizations of the basic Kelvin– Voigt and Maxwell models have been developed. This paper deals with parameter identification for basic and generalized Kelvin–Voigt and Maxwell models for fluid viscous dampers. The identification procedure gives the best mechanical parameters by minimizing a suitable objective function that represents a measure of difference between analytical and experimental applied forces. For this purpose, the particle swarm optimization is adopted. Results are obtained under various test conditions, comparing the agreement of various models with experimental data. Finally, a numerical investigation is performed on a simple one degree of freedom structure, equipped with fluid viscous dampers and subject to a real seismic motion.
TL;DR: In this article, a new double-dot structuring element is constructed for multi-scale mathematical morphology (MM) to extract features from one-dimensional signals, and a correlation analysis gives the final identification result by utilizing information over a whole pattern spectrum.
Abstract: The condition monitoring and fault diagnosis of rolling element bearings play an important role in the safe and reliable operation of rotating machinery. Feature extraction based on vibration signals is an effective means to identify the operating condition of rolling element bearings. Methods based on multi-scale mathematical morphology (MM) have recently been developed to extract features from one-dimensional signals. In this paper, a new double-dot structuring element (SE) is constructed for multi-scale MM. A pattern spectrum, obtained from the multi-scale MM, is used as a feature extraction index. A correlation analysis gives the final identification result by utilizing information over a whole pattern spectrum. Compared with the most commonly used flat SE, the double-dot SE can extract more features of original signals at different scales. Vibration signals, measured from defective bearings with outer race faults, inner race faults and ball faults, are used to evaluate the fault detection ability of ...
TL;DR: In this paper, a sliding-mode controller for a quarter-car active suspension system with uncertainties is proposed, where the nonlinear dynamics of an actuator are considered during the output feedback control design.
Abstract: The nonlinear dynamics of an actuator are considered during the output feedback control design of a quarter-car active suspension system with uncertainties. Because of the complexity of the suspension system with hydraulic actuator dynamics, a simple and effective sliding-mode strategy is employed to obtain both controller and observer. Instead of dividing the system into an actuator subsystem and a suspension subsystem, the system is repartitioned into a linear subsystem and a nonlinear subsystem, which facilitates controller design greatly. By specifying suitable sliding functions for the two subsystems respectively, and forcing the output of the nonlinear subsystem to track the desired fictitious input of the linear subsystem, the sliding-mode controller is created. By Lyapunov theory, robust stability is analyzed. For linear growth vanishing bounded uncertainties and nonvanishing bounded uncertainties, different observer forms are given to simplify the observer in different situations. Based on the co...
TL;DR: In this paper, the authors deal with the study and comparison of the dynamic response of aircraft with passive and active landing gears due to runway irregularities while the aircraft is taxying and compare the performance of the two types of landing gears.
Abstract: This paper deals with the study and comparison of the dynamic response of aircraft with passive and active landing gears due to runway irregularities while the aircraft is taxying. This paper devel...
TL;DR: In this paper, the propagation of Love wave in a piezoelectric layer overlying an inhomogeneous half-space was studied, and the numerical values of the dimensionless phase velocities were calculated and presented graphically to illustrate the effects of inhomogeneity, piezolectricity and dielectric constants.
Abstract: The present paper is devoted to study the propagation of Love wave in a piezoelectric layer overlying an inhomogeneous half-space. This paper deals with two different piezoelectric layers, one is an electrically open and another is an electrically short circuit. As mathematical tools, the method of separation of variables and Whittaker’s function are applied to obtain the dispersion equation of Love wave. In a particular case the dispersion equation reduces to the classical equation of Love wave when the layer is not piezoelectric and half-space is homogeneous. The numerical values of the dimensionless phase velocities are calculated and presented graphically to illustrate the effects of inhomogeneity, piezoelectricity and dielectric constants. It is observed that the phase velocities decrease with the increase of inhomogeneity parameters and electricity constant. It is also found that the phase velocity increases with the increases of the dielectric constant. Graphical user interface software has been de...
TL;DR: In this article, a floating raft isolation system is constructed using the transfer matrix method, finite element method, and periodic structure theory to calculate the dynamic response of the system and the dispersion relations of the periodic structure.
Abstract: This paper investigates the suppression of vibration and noise radiation in a flexible raft system through the use of periodic structure theory. A floating raft isolation system is constructed. The transfer matrix method, the finite element method and periodic structure theory are combined to calculate the dynamic response of the system and the dispersion relations of the periodic structure. The effects of substructure resonances on vibration and noise radiation are analyzed. Next, the periodic isolation structure is used to suppress the vibration and noise radiation in the floating raft system. The isolation performance of the combination of periodic structures and continuous isolators are investigated. Additionally, the influences of the parameters of the floating raft system on vibration and noise are discussed. The numerical results demonstrate that vibration and noise are significantly suppressed in stop bands and are not worsened in pass bands.
TL;DR: In this article, real-time hybrid simulation (RTHS) is implemented and verified with a shake table for education and research, which is a practical and economical experimental technique which complements the strengths of computer simulation with physical testing.
Abstract: In this study, as a state of the art testing method, real-time hybrid simulation (RTHS) is implemented and verified with a shake table for education and research. As an application example, the dynamic behavior of a tuned liquid damper (TLD)-structure system is investigated. RTHS is a practical and economical experimental technique which complements the strengths of computer simulation with physical testing. It separates the test structure into two substructures where part of the structure for which a reliable analytical model is not available is tested physically (experimental substructure) and coupled together with the analytical model of the remaining structure (analytical substructure). The implementation of RTHS involves challenges in accurate control of the experimental substructure as well as the synchronization of the signals. The details of the hardware and the software developed and the steps taken to improve the controller are discussed in this paper so that the implementation of RTHS is proper...
TL;DR: In this paper, the authors show that harmonic currents, which are caused by rotor imbalance and sensor runout in active magnetic bearing (AMB) systems, can induce undesirable harmonic vibrations and superfluous power consumption.
Abstract: Harmonic currents, which are caused by rotor imbalance and sensor runout in active magnetic bearing (AMB) systems, can induce undesirable harmonic vibrations and superfluous power consumption. To a...
TL;DR: In this article, a new vibrations supervision approach based on parity space is used, this will guarantee us the optimal availability of this system, the obtained results show clearly how to ensure a reliable and safe operation in gas compression plants to economically recover the transported gas.
Abstract: The purpose of this work is to increase the online availability of industrial gas compression installations. By prevention against the failures in gas turbines, used in this gas compression installation. In this work a new vibrations supervision approach based on parity space is used, this will guarantee us the optimal availability of this system. The obtained results show clearly how to ensure a reliable and safe operation in gas compression plants to economically recover the transported gas.
TL;DR: In this paper, a two-variable first-order shear deformation theory in combination with surface free energy and small scale (size effect) is employed to present a simple and computationally efficient formulation.
Abstract: A two-variable first-order shear deformation theory in combination with surface free energy and small scale (size-effect) is employed to present a simple and computationally efficient formulation f...
TL;DR: In this article, the design, stability analysis and experimental validation of a computationally non-intensive, model-free, intelligent proportionalintegral (iPI) controller for flexible joint control is presented.
Abstract: This paper presents the design, stability analysis and experimental validation of a computationally non-intensive, model-free, intelligent proportional-integral (iPI) controller for flexible joint ...
TL;DR: In this paper, differential-based empirical mode decomposition (DEMD) is introduced into multi-fault diagnosis of a rotor system, which is also more accurate and precise than the traditional EMD method.
Abstract: Multi-fault diagnosis of rotor systems is a topical issue in the research of rotor dynamics. Empirical mode decomposition (EMD) has been introduced in fault diagnosis of rotor systems, which has proved to be usable and efficient in single fault diagnosis of a rotor system. However, in multi-fault diagnosis of a rotor system, because of the existence of a high-frequency fault signal, EMD is not as powerful as the diagnosis of a single fault in dealing with the decomposition of multi-faults. In this paper, differential-based empirical mode decomposition (DEMD) is introduced into multi-fault diagnosis of a rotor system. The analysis consequences show that the combination of any two faults among crack, rub-impact and pedestal looseness in multi-fault diagnosis can be decomposed successfully and efficiently under the application of the DEMD method, which is also more accurate and precise than the traditional EMD method.
TL;DR: In this paper, the stability of a single magnet coupled with an elastic track was investigated on a real-time test platform based on dSPACE, and two kinds of state feedback controllers were developed based on Kalman filters.
Abstract: Through the theoretical analysis and experiments on the test, the levitation control system stability of the MAGLEV vehicle on elastic track was investigated. Firstly, taking the single magnet coupled with elastic track as the object, the corresponding mathematical model and the real-time test platform based on dSPACE were founded. Secondly, two kinds of the state feedback controllers were developed based on Kalman filters, and their influences on the stability of the MAGLEV system were investigated, respectively. The research results show that, if the track has no damping, the controller treating the tracks as fixed cannot make the MAGLEV system steady. However a harder track stiffness enables the system, with a certain track damping, to stabilize. The control method considering the track’s flexibility can soundly maintain the system’s stability even if the track has a relatively soft stiffness and no damping effect. The tests on the real-time test platform verified the effectiveness of the latter contro...
TL;DR: In this article, the axial vibration of double-walled carbon nanotubes (DWCNTs) is studied using nonlocal elasticity theory and the nonlocal constitutive equations of Eringen are used in the formulations.
Abstract: In this study, the axial vibration of double-walled carbon nanotubes (DWCNTs) is studied using nonlocal elasticity theory. The nonlocal constitutive equations of Eringen are used in the formulations. The van der Waals forces are considered in the axial direction.An interaction coefficient is obtained in terms of the previously proposed van der Waals coefficient and effective thickness of the single-walled carbon nanotubes. The effect of various parameters like geometry of nanotubes, van der Waals forces and nonlocal parameters on the axial vibration of DWCNTs is discussed. Some mode shapes are also depicted in order to show the relative motion of the nested tubes. The van der Waals forces have strong effects on the axial vibration characteristics of DWCNTs. The present results can be used in the continuum modeling of nanoscale linear motors and oscillators.
TL;DR: In this article, a new approach of proportional integral derivative (PID) controller tuning via an evolutionary algorithm was presented, which optimally suppresses the vibration of a flexible beam system using
Abstract: This paper presents a new approach of proportional-integral-derivative (PID) controller tuning via an evolutionary algorithm that optimally suppresses the vibration of a flexible beam system using
TL;DR: In this paper, a fuzzy logic integrated sliding mode controller was designed to decrease the vehicle vibrations and hence improve the ride comfort, and the performance of the controller was tested in a biodynamic human-vehicle combined model.
Abstract: Attenuation of the adverse effects of vehicle vibrations on human health is a challenging problem. One common approach to solve this problem is to use various types of controllers in vehicle suspensions. In this study, in order to decrease the vehicle vibrations and hence improve the ride comfort, a fuzzy logic integrated sliding mode controller was designed. The performance of the controller was tested in a biodynamic human-vehicle combined model. The human body was considered as a lumped parameter model and incorporated into a full vehicle model. The biodynamic responses of a human body to vehicle vibrations were analyzed. Performances of the conventional sliding mode and fuzzy integrated sliding mode controllers were compared with those of a passive control strategy. According to the numerical results, the fuzzy sliding mode controller overcame both classic sliding mode and passive control approaches and decreased vehicle vibrations considerably. It can be deduced from the study that active suspension ...