scholarly journals Gearbox damage identification and quantification using stochastic resonance

2017 ◽  
Vol 18 (7) ◽  
pp. 705
Author(s):  
Clement U. Mba ◽  
Stefano Marchesiello ◽  
Alessandro Fasana ◽  
Luigi Garibaldi
Keyword(s):  
Stochastic Resonance ◽  
Damage Identification ◽  
Identification And Quantification

Damage Identification of a Gear Transmission Using Vibration Signatures

2003 ◽  
Vol 125 (2) ◽  
pp. 394-403 ◽  
Author(s):  
F. K. Choy ◽  
D. H. Mugler ◽  
J. Zhou
Keyword(s):  
Wavelet Transform ◽  
Damage Identification ◽  
Gear Tooth ◽  
Diagnostic System ◽  
Vibration Signal ◽  
Transmission System ◽  
Gear Transmission ◽  
Signature Analysis ◽  
Gear Transmission System ◽  
Identification And Quantification

Important advancements in preventive maintenance of rotor-craft gear transmission systems are currently being sought for the development of an accurate machine health diagnostic system. Such a diagnostic system would use vibration or acoustic signals from the gear transmission system for (1) rapid on-line evaluation of gear wear or damage status, and (2) prediction of remaining gear life. Such health diagnostic capabilities would be essential for effective machine event/life management and advance warning before critical component failures. This paper demonstrates the use of vibration signature analysis procedures for health monitoring and diagnostics of a gear transmission system. The procedures used in this paper include (i) the numerical simulation of the dynamics of a gear transmission system with single and multiple tooth damage, (ii) the application of the Wigner-Ville Distribution (WVD) and the Wavelet transform in damage identification and quantification of damaged tooth based on the numerically generated vibration signal, and (iii) the application of both WVD and the Wavelet transform on experimental data at various stage of gear failure obtained from an accelerated gear damage test rig. This paper demonstrates that the developed signature analysis procedure can successfully detect faulty gears in both numerically simulated and experimental tested transmission system. General conclusions on identification and quantification of gear tooth damage are drawn based on the results of this study.

scholarly journals Damage Identification and Quantification in Beams Using Wigner-Ville Distribution

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6638
Author(s):  
Andrzej Katunin
Keyword(s):  
Damage Identification ◽  
Boundary Effect ◽  
Parametric Method ◽  
High Sensitivity ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Novel Method ◽  
Local Stiffness ◽  
Non Destructive ◽  
Identification And Quantification

The paper presents the novel method of damage identification and quantification in beams using the Wigner-Ville distribution (WVD). The presented non-parametric method is characterized by high sensitivity to a local stiffness decrease due to the presence of damage, comparable with the sensitivity of the wavelet-based approaches, however the lack of selection of the parameters of the algorithm, like wavelet type and its order, and the possibility of reduction of the boundary effect make this method advantageous with respect to the mentioned wavelet-based approaches. Moreover, the direct relation between the energy density resulting from the application of WVD to modal rotations make it possible to quantify damage in terms of its width and depth. The results obtained for the numerical modal rotations of a beam presented in this paper, simulating the results of non-destructive testing achievable with the shearography non-destructive testing method, confirm high accuracy in localization of a damage as well as quantification of its dimensions. It was shown that the WVD-based method is suitable for detection of damage represented by the stiffness decrease of 1% and can be identified and quantified with a high precision. The presented results of quantification allowed extracting information on damage width and depth.

Development of a Rapid Survey Method of Sampling and Analysis for Asbestos in Ambient Air

1972 ◽  
Vol 30 ◽  
pp. 630-631 ◽  
Author(s):  
R. E. Heffelfinger ◽  
C. W. Melton ◽  
D. L. Kiefer ◽  
W. M. Henry ◽  
R. J. Thompson
Keyword(s):  
Neutron Activation ◽  
Ambient Air ◽  
Survey Method ◽  
Potential Hazard ◽  
Transmission Microscopy ◽  
Comparative Analyses ◽  
Asbestos Fibers ◽  
Controlled Conditions ◽  
Unequivocal Identification ◽  
Identification And Quantification

A methodology has been developed and demonstrated which is capable of determining total amounts of asbestos fibers and fibrils in air ranging from as low as fractional nanograms per cubic meter (ng/m3) of air to several micrograms/m3. The method involves the collection of samples on an absolute filter and provides an unequivocal identification and quantification of the total asbestos contents including fibrils in the collected samples.The developed method depends on the trituration under controlled conditions to reduce the fibers to fibrils, separation of the asbestos fibrils from other collected air particulates (beneficiation), and the use of transmission microscopy for identification and quantification. Its validity has been tested by comparative analyses by neutron activation techniques. It can supply the data needed to set emissions criteria and to serve as a basis for assessing the potential hazard for asbestos pollution to the populace.

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