Diagnostics of Shaft Trains of Large Turbine Sets for Integrity Using Torsional Vibration Measurements

Nazolin, A. L.; Polyakov, V. I.; Gnezdilov, S. G.

doi:10.1134/s004060152001005x

Cited by 6 publications

(3 citation statements)

References 3 publications

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“…used wavelet transform to analyze the time–frequency characteristics of machine tool spindle vibration signal, but the essence of wavelet transform is Fourier transform with adjustable window. Once the local feature scale of the signal is smaller than the feature scale of the selected base wavelet, it is difficult to accurately describe the local features with strong non‐stationary in the spindle vibration signal of NC machine tool due to working condition change or fault [23, 24]. The authors of [41] are concerned with the construction of a new fractional‐order controller for the autonomous rudder of underactuated surface vessels.…”

Section: Literature Reviewmentioning

confidence: 99%

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Mechanical vibration monitoring system for electrocardiogram machine based on Hilbert‐Huang transformations

Zhu

Samori

2022

The Journal of Engineering

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The monitoring of health and the technologies that are related to it are an exciting area of research. The paper proposes a mechanical manufacturing vibration monitoring system that is based on Hilbert-Huang transformation (HHT) feature extraction to monitor the running state of the spindle of a mechanical numerical control (NC) machine tool of an electrocardiogram (ECG) machine. Real-time monitoring of the time-frequency characteristic quantity of the spindle vibration signal for ECG signals has been made possible due to the online empirical mode decomposition (EMD) method, which is used to obtain the time-frequency characteristic quantity of the spindle vibration signal based on HHT. The experiment shows that the frequency doubling characteristic components in the timefrequency distribution are obvious in the time interval without copper rod contact, but they disappear in the time interval during which copper rods are in contact (0.3 1.1 s, 3 4s in the figure). It has been demonstrated that the system is capable of not only accurately monitoring the characteristic quantity in the frequency domain of the vibration signal produced by the NC machine tool spindle, but also of successfully implementing the monitoring of the time-frequency characteristic quantity in real time.

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Section: Literature Reviewmentioning

confidence: 99%

“…In recent years, the vibration monitoring method of NC machine tool spindle has been widely studied, and the corresponding monitoring system has been developed. [23,24]. The authors of [41] are concerned with the construction of a new fractional-order controller for the autonomous rudder of underactuated surface vessels.…”

Section: Literature Reviewmentioning

confidence: 99%

Mechanical vibration monitoring system for electrocardiogram machine based on Hilbert‐Huang transformations

Zhu

Samori

2022

The Journal of Engineering

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“…It is used for both the monitoring of faulty machines [ 6 , 19 , 20 ] and the design of innovative torsional dampers to be applied on long shafts lines [ 21 , 22 ]. Usually strain gauges and phonic wheels are used for experimental measurements [ 23 , 24 ], but they require an invasive and dedicated set-up. Bell et al [ 16 ] used laser vibratomes in real-world applications but they limited the measurements to only one section of the machine.…”

Section: Introductionmentioning

confidence: 99%

Torsional Vibration Analysis Using Rotational Laser Vibrometers

Chatterton,

Dassi,

Gheller

et al. 2024

Sensors

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Torsional vibration is a critical phenomenon in rotor dynamics. It consists of an oscillating movement of the shaft and causes failures in multiple oscillating fields of application. This type of vibration is more difficult to measure than lateral vibration. Torsional vibrometers are generally invasive and require a complicated setup, as well as being inconvenient for field measurements. One of the most reliable, non-invasive, and transportable measuring techniques involves the laser torsional vibrometer. For this research, two laser heads with different measurement capabilities were utilized. An experimental test rig was used to perform a relative calibration of the two laser vibrometers. The frequency of the acting force and the rotation speed of the shaft vary in the same range, which is commonly found in rotating machines. Finally, experimental measurements of torsional vibrations using laser vibrometers were compared with numerical results from a 1D finite element model of the same test rig. The main outcome of this paper is the definition of a reliable measuring procedure to exploit two laser vibrometers for detecting torsional mode-shapes and natural frequencies on real machines. The relative calibration of two different measuring heads is described in detail, and the procedure was fundamental to properly correlate measuring signals in two machine sections. A good correspondence between the numerical and experimental results was found.

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