Showing papers in "Mechanical Systems and Signal Processing in 2006"

TL;DR: This paper attempts to summarise and review the recent research and developments in diagnostics and prognostics of mechanical systems implementing CBM with emphasis on models, algorithms and technologies for data processing and maintenance decision-making.

TL;DR: In this article, the spectral kurtosis (SK) was used to detect and characterize nonstationary signals in the presence of strong masking noise and to detect incipient faults in rotating machines.

TL;DR: In this article, a review of the past and recent developments in system identification of nonlinear dynamical structures is presented, highlighting their assets and limitations and identifying future directions in this research area.

TL;DR: A formalisation of the spectral kurtosis by means of the Wold–Cramer decomposition of “conditionally non-stationary” processes is proposed, which engenders many useful properties enjoyed by the SK.

TL;DR: The new trends on Laser Doppler Vibrometry (LDV) development are outlined with particular attention to the innovative solutions answering to the most recent technological requirements which are not met by the current systems as discussed by the authors.

TL;DR: In this paper, an experimental investigation reported in this paper was centred on the application of the acoustic emission (AE) technique for identifying the presence and size of a defect on a radially loaded bearing.

TL;DR: In this article, the authors applied the empirical mode decomposition (EMD) and Hilbert spectrum for adaptive analysis of non-linear and non-stationary signals for gearbox fault diagnosis.

TL;DR: In this article, the authors proposed a new fault detection method that combines Hilbert transform and wavelet packet transform for gearbox demodulation, which can extract modulating signal and help to detect the early gear fault.

TL;DR: In this article, an experimental investigation has been carried out in order to evaluate the detection of cavitation in actual hydraulic turbines, based on the analysis of structural vibrations, acoustic emissions and hydrodynamic pressures measured in the machine.

TL;DR: In this article, a multi-stage transmission gearbox (with and without defects) has been studied in order to replace the conventional vibration monitoring by MCSA, and it has been observed through FFT analysis that low frequencies of the vibration signatures have sidebands across line frequency of the motor current whereas high frequencies of vibration signature are difficult to be detected.

TL;DR: A critical survey and comparison ofparametric time-domain methods for non-stationary random vibration modelling and analysis based upon a single vibration signal realization confirms the advantages and high performance characteristics of parametric methods.

TL;DR: In this article, a general description of smart material systems is given, focusing on the following fields of application: semi-passive concepts, energy harvesting, semi-active concepts, active vibration control and active structural acoustic control.

TL;DR: The efficiency of the proposed system is demonstrated by detecting motor electrical and mechanical faults originated from the induction motors by using Dempster–Shafer theory and it has potential for real-time applications.

TL;DR: In this article, the authors proposed a new fault feature extraction approach based on empirical mode decomposition (EMD) method and autoregressive (AR) model for roller bearings.

TL;DR: A new multi-class classification of SVM named ‘one to others’ algorithm is presented to solve the multi- class recognition problems and the effectiveness of the method is verified by the application to the fault diagnosis for turbo pump rotor.

TL;DR: In this article, an energy difference tracking method is proposed to define the intrinsic mode function (IMF) in the EMD method, based on the integrity and orthogonality of the EMF.

TL;DR: In this article, a 26 degree of freedom gear dynamic model of three shafts and two pairs of spur gears in mesh for comparison of localised tooth spalling and damage is presented.

TL;DR: In this article, the theory of stochastic model updating using a Monte-Carlo inverse procedure with multiple sets of experimental results is explained and then applied to the case of a simulated three degree-of-freedom system, which is used to fix ideas and also to illustrate some of the practical limitations of the method.

TL;DR: In this paper, the authors present an on-line current monitoring system that uses both techniques for fault detection and diagnosis in the stator and in the rotor of three phase induction motors.

TL;DR: In this paper, the state of the art of the mathematical theory of vibration absorption is presented and illustrated for the benefit of the reader with numerous simple examples, including structural modification by passive elements and active control.

TL;DR: In this article, a model-based transverse crack identification method for industrial machines is presented, which is validated by experimental results obtained on a large test rig, which was expressly designed for investigating the dynamic behavior of cracked horizontal rotors.

TL;DR: In this paper, a method based on the finite element vibration analysis is presented for defect detection in rolling element bearings with single or multiple defects on different components of the bearing structure using the time and frequency domain parameters.

TL;DR: In this article, a damage detection method of mechanical system based on subspace identification concepts and statistical process techniques is presented, where measured time-responses of structures subjected to artificial or environmental vibrations are assembled to form the Hankel matrix, which is further factorised by performing singular value decomposition to obtain characteristic subspaces.

TL;DR: In this paper, the instantaneous energy density is shown to obtain high values when defected teeth are engaged, and three methods are compared in terms of sensitivity, reliability and computation effectiveness.

TL;DR: In this article, the authors proposed a novel technique for state detection of gearbox, which fits a time-varying autoregressive model to the gear motion residual signals applying a noise-adaptive Kalman filter, in the healthy state of the target gear.

TL;DR: A new envelope algorithm, the segment power function method, is put forward that is superior to existing algorithms because in most situations it is more flexible than the cubic spline interpolation algorithm and smoother than the Akima interpolation algorithms, and it is less likely to introduce a false frequency when applied to HHT.

TL;DR: In this article, a non-linear model based on complex radial basis function (RBF) networks is proposed for the reconstruction of in-cylinder pressure pulse waveforms, where the Fourier transforms of both engine structure vibration and crankshaft speed fluctuation are used for reconstruction process.

TL;DR: In this paper, the electro-mechanical coupling of typical MEMS devices is defined and introduced, followed by an in-depth review of the various existing modeling and simulation techniques.

TL;DR: This novel MCM method is based on Kohonen's self-organising map and adopts a multidimensional dissimilarity measure for dual class classification and designed to be highly modular and scale well for a multi-sensor condition monitoring environment.

TL;DR: In this paper, an extension to higher-order describing functions is realized by introducing the concept of the harmonics generator, which relates the magnitude and phase of the higher harmonics of the periodic response of the system to the magnitude of a sinusoidal excitation.