Bearing faults are one of the most common inducements for machine failures. Therefore, it is very important to perform bearing fault diagnosis reliably and rapidly. However, fundamental but difficult extract impulses buried in heavy background noise diagnosis. In this paper, a novel adaptive enhanced sparse period-group lasso (AdaESPGL) algorithm proposed. The based on proposed group penalty, which promotes sparsity within across groups impulsive feature faults. Moreover, periodic prior...

Blade tip timing (BTT) is an effective noncontact measurement technology for rotating blade health monitoring. However, due to the mismatching between high-speed rotation and limited amount of probes, signal collected from BTT system severely undersampled, which induces difficulty in feature extraction. Multiple classification (MUSIC) has potential overcome undersampled problem once probes are properly placed. Whereas, if traditional MUSIC directly used BTT, accuracy frequency identification...

Blade tip timing (BTT) methods have been increasingly implemented for blade health monitoring (BHM). However, there are two drawbacks of current signal analysis preventing them from applying to online monitoring: first, requires the manual judgment resonance region, which is time-consuming. Second, existing BTT not suitable monitoring. The spectral-analysis-based method presents spectral aliasing, while computational complexity sparse-based usually high. In this article, we propose an...

Abstract This study aims at the systematical improvement and comparative analysis of analytical crack models for rotating blade. Part I this focuses on modeling, model modification, validation transverse The most widely applied blade are reviewed compared, then their limitations discussed. It is indicated that conventional suffer from low physical interpretability vibration prediction accuracy. By considering these models, modification performed to enhance meaning improve First, stress-based...

The harsh working environment of compressor threats the integrality bladed disk. Crack is one most fatal faults rotating blades. Detecting crack blades at early stage could ensure safe operation gas turbine and save economic costs. Blade tip timing (BTT) a noncontact blade vibration measurement technique, which widely used in recent years. In this article, procedure detection using BTT data proposed. First, some typical parameters are taken into consideration, including resonance frequency,...

Blade health monitoring (BHM) is an important technology to ensure the safe operation of turbine machinery. The blade tip timing (BTT) method a non-contact approach vibration that widely used for aero-engines. A BTT signal can be characterized as non-uniform and sub-Nyquist sampled (i.e., under-sampled). For sampling, least squares (LS) fitting has long been reconstruct spectrum. However, under-sampling causes spectrum obtained by LS aliasing. iterative reweighted periodogram (IRLSP)...

Abstract This study aims at the comparative analysis and improvement of different analytical crack models for rotating blade. Part II this focuses on dynamic characteristics based modified mentioned in I. A nonlinear damage indicator (NDI) an equivalent energy (EEI) are introduced to characterize effect from perspectives. EEI offers a physical mechanism explanation closing behavior, which is invisible. Meanwhile, NDI observable quantify nonlinearity crack. It demonstrated through numerical...

Rotating blade is one of the most important components for turbomachinery. Blade crack common and dangerous failure modes rotating blade. Therefore, fault mechanism feature extraction are vital safety assurance This study aimed at nonlinear dynamic model with transverse prior faults based on vibration responses. First foremost, a high-fidelity breathing (HFBCM) proposed basis criterion stress states section. Since HFBCM physically deduced from perspective energy dissipation coupling between...

Blade tip timing (BTT) is a promising vibration measurement technique for rotating blades owing to its noncontact nature, high efficiency, and long service life. However, due the mismatch between frequency of low achievable sampling frequency, BTT inherently undersampled thus results in difficulties subsequent parameter identification. To address this critical issue application technique, we proposed concept statistical which promotes efficient layouts identification methods by shifting...

Vibration signal analysis has become one of the important methods for machinery fault diagnosis. The extraction weak features from vibration signals with heavy background noise remains a challenging problem. In this article, we first introduce idea algorithm-aware sparsity-assisted feature enhancement, which extends model-aware diagnosis and allows more flexible convenient algorithm design. framework methods, define generalized structured shrinkage operators construct (GSSA) to overcome...

Blade tip timing (BTT) is a noncontacting vibration measurement method for rotating blade condition monitoring. The BTT sampling frequency proportional to the number of probes under uniform probe layout and constant speed. However, limitation installation space in aeroengines causes lack probes, which leads inherent undersampled feature signal. Thus, identification nonuniform signal has become popular field processing. Multiple classification (MUSIC) an array processing that been applied...

Blade tip timing (BTT) is a noncontact blade vibration measurement method for rotating condition monitoring. However, it difficult to install once-per-revolution (OPR) probe due the internal environment limitation of an engine. To solve this problem, OPR-free BTT proposed in article. Compared with existing methods that are based on displacement, spacing change (BSC). In addition, layout selection minimum redundancy linear array (MRLA) introduced reduce acquired signal. Simulations conducted...

Rotating blades play a functional role during the operation of an aero-engine. To ensure safety, it is urgently needed to monitor blade condition. Blade tip timing (BTT) potential vibration measurement technique for rotating owing its non-contact and efficiency. However, undersampling characteristic BTT signal hinders sub-sequent processing condition monitoring fault diagnosis. In this paper, autocorrelation/covariance samples replaced spectrum reconstruction. On basis, we proposed...