Synchrosqueezing transform (SST) is a currently proposed novel postprocessing time-frequency (TF) analysis tool. It has been widely shown that SST able to improve TF representation. However, so far, how the resolution while ensuring accuracy of signal reconstruction still an open question, particularly for vibration with time-varying instantaneous frequency (IF) characteristics, due fact signals mechanical equipment usually contain many types noise generated by harsh operating conditions,...

An algorithm based on correlation analysis was adopted to estimate the probability of presence damage in aluminum plates using Lamb wave signals from an active sensor network. Both finite element and experimental evaluations were presented. The Shannon entropy optimization criterion applied calibrate optimal mother wavelet most appropriate continuous transform scale for signal processing. coefficients individual sensing paths between present state (with damage) reference (without calculated,...

Time-frequency analysis (TFA) is considered as a useful tool to extract the time-variant features of nonstationary signal. In this paper, new method called demodulated high-order synchrosqueezing transform (DHST) proposed. The DHST introduces two-step algorithm, namely, and achieve compact time-frequency representation (TFR) while enabling reconstruction signal from TFR. performance proposed in paper validated by both simulated experimental signals including bat echolocation vibration...

The rolling element bearing is easy to be malfunctioning due the harsh operation. When a fault exists in bearing, it can generate periodical or quasi-periodical impulses, which are important features for detection. These impulses may submerged background noise and interferences of other unrelated components. spectral kurtosis, its fast realization, kurtogram, have been widely used diagnosis by extracting impulsive feature. However, performance weakened fixed decomposition scheme prior...

Time-frequency analysis (TFA) is regarded as an efficient technique to reveal the hidden characteristics of oscillatory signal. At present, traditional TFA methods always construct signal model in time domain and assume instantaneous features modes be continuous. Thus, most these approaches fail tackle some specific kinds impulselike signal, including shock vibration waves, damped tones, or marine mammals. This article introduces a new method called generalized horizontal synchrosqueezing...

Signal processing plays a pivotal role in fault diagnostics of mechanical systems. An approach, viz. wavelet transform-based higher-order statistics, was developed this paper for diagnosis rolling element bearings. In the transform (discrete and packet transform) introduced into fourth-order statistic, kurtosis. Thereinto, discrete kurtosis (DWTK) applied to signals get higher resolution low-frequency bands1 on other hand, (WPTK) obtain relatively high high-frequency bands comparison with...

Structural health monitoring (SHM) system, usually consisting of a sensor network for collecting the structural response signal and data analysis algorithms interpreting signal, plays significant role in fatigue life damage accumulation prognostics. Wavelet transform (WT) has gained popularity as an efficient means processing SHM, which optimal mother wavelet-based WT can carry out feature extraction with high precision. This article is to provide criteria wavelet selection Lamb wave...

Guided wave detection using different fiber optic sensors and their applications in damage for composite laminates were systematically investigated compared this paper. Two types of sensors, namely Bragg gratings (FBG) Doppler effect-based (FOD) addressed guided systems constructed both types. waves generated by a piezoelectric transducer propagated through quasi-isotropic carbon reinforced plastic (CFRP) laminate acquired these sensors. Characteristics ultrasonic compared. Results...

With the objective of improving temperature stability quantitative comparison Lamb wave signals captured in different states, a damage diagnostic imaging algorithm integrated with Shannon-entropy-based interrogation was proposed. It evaluated experimentally by identifying surface stiffener-reinforced CF/EP quasi-isotropic woven laminate. The variations Shannon entropy reference (without damage) and present (with from individual sensing paths were calibrated as signatures utilized to estimate...

Wind turbines usually operate under nonstationary conditions, such as wide-range speed fluctuation and time-varying load. Its critical component, the planetary gearbox, is prone to malfunction or failure, which leads downtime repair costs. Therefore, fault diagnosis condition monitoring for gearbox in wind a vital research topic. Meanwhile, signals measured by vibration sensors mounted exhibit features. In this study, novel time-frequency method based on high-order synchrosqueezing transform...

The empirical wavelet transform (EWT) has shown its effectiveness in some applications. However, when noisy and nonstationary signals are analyzed, local maxima may appear be retained the peak sequence mistakenly, so improper segmentation frequency domain will occur. In our research, morphological EWT (MEWT) method is proposed based on filters (MFs) 1-D Otsu to mitigate boundary drawback of EWT, it can applied chatter detection because good performance finding optimal band. First,...

In this paper, the dispersion of Lamb waves in aluminum structures was systematically analyzed to differentiate mode each package wave signals and localize damage. Piezoelectric transducers were bonded on surfaces structures, functioning as actuator sensor excite acquire waves, respectively. Wavelet transform applied acquired signals, which optimal mother wavelet selected using concept Shannon entropy obtain most accurate location package. The ridge contour time-scale domain obtained...

A three‐dimensional spectral element method (SEM) was developed for analysis of Lamb wave propagation in composite laminates containing a delamination. SEM is more efficient simulating structures than conventional finite (FEM) because its unique diagonal form the mass matrix. Three types laminates, namely, unidirectional‐ply cross‐ply and angle‐ply are modeled using elements. Wave characteristics intact investigated, effectiveness validated by comparison simulation results with analytical...

An integration of time-reversal Lamb wave signals from a sensor network and damage diagnostic imaging algorithm is developed to identify dual notches in an aluminum plate. The time reversibility waves for one propagation path plate investigated using dynamic finite element analysis (FEA). A time-reversal-based index (DI) calibrated by correlation the reconstructed waveform original activated tone burst, when fundamental symmetric (S 0 ) mode alone reversed or both S antisymmetric (A are...

In this paper, a fault diagnosis method that is based on the deep structure and sparse least squares support vector machine (SLSSVM) proposed. This constructs of multi-layer (SVM). First, SVM first layer trained by using training samples, it learns shallow features data. Then, "feature extraction formula" used to generate new expression sample, which as input next layer. The trains extracts signal layer; eventually, after multiple feature mapping, outputs diagnostic results last Because...

This article introduces the second-order transient-extracting transform (TET2) to extract transient components from a nonstationary signal. Different traditional (TET1), proposed method is based on more general frequency-domain signal model, termed Gaussian-modulated linear group delay model. The first step of computation (GD) estimator that describes temporal positioning ridges in time-frequency (TF) plane. Based this GD estimator, we can then obtain an energy-concentrated TF...