Structural Health Monitoring, Structural Dynamics, Smart materials and Structures, Advanced signal processing, Machine learning
357
Scopus Publications
Scopus Publications
Cointegration Approach for Vibration-Based Misalignment Detection in Rotating Machinery Under Varying Load Conditions Sylwester Szewczyk, Roman Barczewski, Wiesław J. Staszewski, Damian Janiga, Phong B. Dao Sensors, 2025 Shaft misalignment is among the most common faults in rotating machinery, and although many diagnostic methods have been proposed, reliably detecting it under varying load conditions remains a major challenge for vibration-based techniques. To address this issue, this study proposes a new vibration-based misalignment detection framework that leverages cointegration analysis. The approach examines both the stationarity of vibration signals and the residuals derived from the cointegration process. Specifically, it combines the Augmented Dickey–Fuller (ADF) test with cointegration analysis in three stages: (1) applying the ADF test to raw vibration data before cointegration, (2) performing cointegration on the vibration time series, and (3) reapplying the ADF test to the post-cointegrated data. The method was validated using experimental measurements collected from a laboratory-scale test rig comprising a motor, gearbox, and hydraulic gear pump, tested under both healthy and misaligned states with varying degrees of severity. Vibration signals were recorded across multiple load conditions. The results demonstrate that the proposed method can successfully detect misalignment despite load variations, while also providing insights into fault severity. In addition, the residuals from the cointegration process proved to be highly sensitive to damage, highlighting their value as features for vibration-based condition monitoring.
Evaluation of Material Integrity Using Higher-Order Harmonic Generation in Propagating Shear Horizontal Ultrasonic Waves Rafał Radecki, Wiesław J. Staszewski Materials, 2024 Material nonlinearity is explored for the assessment of structural integrity. Crack–wave interactions are of particular interest. The major focus is on higher-order harmonics, generated in propagating shear horizontal (SH) waves. These harmonics are generated due to global material nonlinearity and local effects such as fatigue cracks. The theoretical background of the proposed method is explained. The method is examined using numerical simulations and experimental tests. The former involves the Local Interaction Simulation Approach (LISA), implemented for the nonlinear shear horizontal wavefield. The latter is based on a high-frequency shear excitation approach. Experimental tests are conducted using a series of beam specimens with fatigue cracks. Low-profile, surface-bonded piezoceramic shear actuators are used for excitation. The excitation frequency is selected to minimize the number of generated modes in the examined specimens. Nonlinear ultrasonic responses are collected using a non-contact laser vibrometer. The results show that higher-order harmonic generation—based on shear horizontal wave propagation—can be used for crack detection in the presence of global material nonlinearity.
Directivity and Excitability of Ultrasonic Shear Waves Using Piezoceramic Transducers—Numerical Modeling and Experimental Investigations Emil Aleksiewicz-Drab, Aleksandra Ziaja-Sujdak, Rafał Radecki, Wiesław J. Staszewski Sensors, 2024 In this paper, piezoceramic-based excitation of shear horizontal waves is investigated. A thickness-shear d15 piezoceramic transducer is modeled using the finite-element method. The major focus is on the directivity and excitability of the shear horizontal fundamental mode with respect to the maximization of excited shear and minimization of Lamb wave modes. The results show that the geometry of the transducer has more effect on the directivity than on the excitability of the analyzed actuator. Numerically simulated results are validated experimentally. The experimental results show that transducer bonding significantly affects the directivity and amplitude of the excited modes. In conclusion, when the selected actuator is used for shear excitation, the best solution is to tailor the transducer in such a way that at the resonant frequency the desired directivity is achieved.
Damage Detection in Glass Fibre Composites Using Cointegrated Hyperspectral Images Jan Długosz, Phong B. Dao, Wiesław J. Staszewski, Tadeusz Uhl Sensors, 2024 Hyperspectral imaging (HSI) is a remote sensing technique that has been successfully applied for the task of damage detection in glass fibre-reinforced plastic (GFRP) materials. Similarly to other vision-based detection methods, one of the drawbacks of HSI is its susceptibility to the lighting conditions during the imaging, which is a serious issue for gathering hyperspectral data in real-life scenarios. In this study, a data conditioning procedure is proposed for improving the results of damage detection with various classifiers. The developed procedure is based on the concept of signal stationarity and cointegration analysis, and achieves its goal by performing the detection and removal of the non-stationary trends in hyperspectral images caused by imperfect lighting. To evaluate the effectiveness of the proposed method, two damage detection tests have been performed on a damaged GFRP specimen: one using the proposed method, and one using an established damage detection workflow, based on the works of other authors. Application of the proposed procedure in the processing of a hyperspectral image of a damaged GFRP specimen resulted in significantly improved accuracy, sensitivity, and F-score, independently of the type of classifier used.
Wavelet-based transmissibility for structural damage detection Kajetan Dziedziech, Krzysztof Mendrok, Tadeusz Uhl, Wiesław J. Staszewski Current Perspectives and New Directions in Mechanics Modelling and Design of Structural Systems Proceedings of the 8th International Conference on Structural Engineering Mechanics and Computation 2022, 2023
