Crack detection for a Jeffcott rotor with a transverse crack: An experimental investigation

Guo, Chaozhong; Yan, Jihong; Yang, Wei-Cheng

doi:10.1016/j.ymssp.2016.06.011

Cited by 70 publications

(44 citation statements)

References 29 publications

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“…When the rotor passes through 1/3 or 1/2 sub-resonance region, the orbit phase rotates nearly 90 • . The behaviors agree with the experiment results in [50] and numerical results in [58], which can verify the correctness of the model and its solution in this paper.…”

Section: Modelling and Validation Of A Two-disc Rotor With A Breathinsupporting

confidence: 86%

“…Energy variation of the 3× component (where X represents the frequency corresponding to the rotating speed) extracted based on Wavelet Packet Transform [43][44][45] was used to quantify the crack depth of a crack with known crack location in a rotor by Gómez et al [46], and the analytical Jeffcott rotor model and the corresponding experimental rotor with a saw-cut crack were studied to validate the method. EMD method [47][48][49] was applied to steady-state responses generated from a Jeffcott rotor to extract the 3× and 2× components in the neighborhood of 1/3 and 1/2 of the critical rotating speed by Guo et al [50], results showed that the variation of averaged amplitudes of super-harmonic components provided clear and robust signatures of early cracks in rotating rotors. However, from the literature, few researches have been carried out to identify both the location and depth of a crack in a rotor with these super-harmonic features.…”

Section: Introductionmentioning

confidence: 99%

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A Super-Harmonic Feature Based Updating Method for Crack Identification in Rotors Using a Kriging Surrogate Model

Ouyang

2019

Applied Sciences

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Dynamic model updating based on finite element method (FEM) has been widely investigated for structural damage identification, especially for static structures. Despite the substantial advances in this method, the key issue still needs to be addressed to boost its efficiency in practical applications. This paper introduces the updating idea into crack identification for rotating rotors, which has been rarely addressed in the literature. To address the problem, a novel Kriging surrogate model-based FEM updating method is proposed for the breathing crack identification of rotors by using the super-harmonic nonlinear characteristics. In this method, the breathing crack induced nonlinear characteristics from two locations of the rotors are harnessed instead of the traditional linear damage features for more sensitive and accurate breathing crack identification. Moreover, a FEM of a two-disc rotor-bearing system with a response-dependent breathing crack is established, which is partly validated by experiments. In addition, the associated breathing crack induced nonlinear characteristics are investigated and used to construct the objective function of Kriging surrogate model. Finally, the feasibility and the effectiveness of the proposed method are verified by numerical experiments with Gaussian white noise contamination. Results demonstrate that the proposed method is effective, accurate, and robust for breathing crack identification in rotors and is promising for practical engineering applications.

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Section: Modelling and Validation Of A Two-disc Rotor With A Breathinsupporting

confidence: 86%

Section: Introductionmentioning

confidence: 99%

A Super-Harmonic Feature Based Updating Method for Crack Identification in Rotors Using a Kriging Surrogate Model

Ouyang

2019

Applied Sciences

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“…This phenomenon, well-known by research scientists dealing with cracked rotors dynamics, was also observed by Gasch [14] and Patel and Darpe [27] by using a switching crack model. This change of the whirl orbit shape during the passage through one-half and one-third of the first critical rotating frequency has been experimentally observed in [32,29,16]. Also, in previous works ( [11,13,12,8]), we have made similar observation with a more realistic breathing mechanism of the crack.…”

Section: Saber El Aremsupporting

confidence: 85%

“…The last three systems of equations completely describe the shaft oscillations. Equations (15) and (16) show that the coupling between the transverse oscillations is due only to the shocks with velocity jumps. At each shock, the system accelerates or decelerates to maintain the imposed rotating frequency Ω .…”

Section: Saber El Aremmentioning

confidence: 99%

Nonlinear analysis, instability and routes to chaos of a cracked rotating shaft

Arem

2019

Nonlinear Dyn

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is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. This is an author-deposited version published in: https://sam.ensam.eu Handle IDAbstract The aim of this paper is to explore the dynamical response of a rotating shaft with a cracked transverse section. This complex problem is distilled down to the study of a very comprehensive mechanical system composed of two non-cracked rigid bars connected with a nonlinear bending spring that concentrates the global stiffness of the cracked shaft. The switching crack model is presented as a specific case of the EDF-LMS family of models and adopted to describe the breathing mechanism of the crack. By analyzing the system equilibrium equations, we show that the stiffness change when the crack breathes leads to shocks with velocity jumps and coupling between the transverse oscillations. The linear stability of the periodic solutions is examined based on the Floquet's theory. Nonlinear dynamics tools such as Poincaré maps and bifurcation diagrams are used to unveil the system oscillations characteristics. Many well-known features due to the crack presence have been observed, but some unexpected responses are noticed like chaotic behavior. This can be confidently attributed to the abrupt change of the structure stiffness with the breathing crack. It has also been observed that with the super-harmonic resonance phenomenon, the increase of static deflection accompanied by that of the first two harmonics amplitudes are good indicators of a propagating crack presence.

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“…A lot of model and signal based methods have been proposed to solve the fault detection problem for machines [18][19][20] and robots [21,22]. In this paper, the vibration signals are used to find the optimal dynamic motion parameters.…”

Section: Introductionmentioning

confidence: 99%

Reducing the Frame Vibration of Delta Robot in Pick and Place Application: An Acceleration Profile Optimization Approach

Cheng

Wei

2018

Shock and Vibration

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Delta robot is typically mounted on a frame and performs high speed pick and place tasks from top to bottom. Because of its outstanding accelerating capability and higher center of mass, the Delta robot can generate significant frame vibration. Existing trajectory smoothing methods mainly focus on vibration reduction for the robot instead of the frame, and modifying the frame structure increases the manufacturing cost. In this paper, an acceleration profile optimization approach is proposed to reduce the Delta robot-frame vibration. The profile is determined by the maximum jerk, acceleration, and velocity. The pick and place motion (PPM) and resulting frame vibration are analyzed in frequency domain. Quantitative analysis shows that frame vibration can be reduced by altering those dynamic motion parameters. Because the analytic model is derived based on several simplifications, it cannot be directly applied. A surrogate model-based optimization method is proposed to solve the practical issues. By directly executing the PPM with different parameters and measuring the vibration, a model is derived using Gaussian Process Regression (GPR). In order to reduce the frame vibration without sacrificing robot efficiency, those two goals are fused together according to their priorities. Based on the surrogate model, a single objective optimization problem is formulated and solved by Genetic Algorithm (GA). Experimental results show effectiveness of the proposed method. Behavior of the optimal parameters also verifies the robot-frame vibration mechanism.

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Crack detection for a Jeffcott rotor with a transverse crack: An experimental investigation

Cited by 70 publications

References 29 publications

A Super-Harmonic Feature Based Updating Method for Crack Identification in Rotors Using a Kriging Surrogate Model

A Super-Harmonic Feature Based Updating Method for Crack Identification in Rotors Using a Kriging Surrogate Model

Nonlinear analysis, instability and routes to chaos of a cracked rotating shaft

Reducing the Frame Vibration of Delta Robot in Pick and Place Application: An Acceleration Profile Optimization Approach

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