Magnetic Nondestructive Evaluation of Bending Fatigue Damage Using the Drag Force Method

Abstract Nitriding is a case-hardening process used for alloy steel gears and is quite similar to case carburizing. Nitriding of gears can be done in either a gas or liquid medium containing nitrogen. This chapter discusses the processes involved in gas nitriding. It reviews the effects of white layer formation in nitrided gears and presents general recommendations for nitrided gears. The chapter describes the microstructure, overload and fatigue damage, bending-fatigue life, cost, and distortion of nitrided gears. Information on nitriding steels used in Europe and the applications of nitrided gears are also provided. The chapter presents case studies on successful nitriding of a gear and on the failure of nitrided gears used in a gearbox subjected to a load with wide fluctuations.

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Nondestructive Evaluation of Composite Structures Using System Identification Technique

Journal of Engineering Materials and Technology ◽

10.1115/1.3226021 ◽

1988 ◽

Vol 110 (2) ◽

pp. 134-139 ◽

Cited By ~ 12

Author(s):

W. H. Tsai ◽

J. C. S. Yang

Keyword(s):

System Identification ◽

Nondestructive Test ◽

Nondestructive Evaluation ◽

Fatigue Damage ◽

Composite Structures ◽

Impact Damage ◽

Epoxy Ring ◽

System Parameters ◽

Identification Technique

A system identification technique is presented for nondestructive test to detect and to characterize the existence and location of cracks and other damages in composite structures. Various composite structures, including Kevlar-epoxy plate, graphite epoxy ring, and graphite-epoxy coupon have been tested for different damages such as crack, delamination, impact damage, fatigue damage, etc. In addition, the correlation between severity of any type of the damages mentioned above and changes in identified system parameters has also been systematically studied.

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Magnetic nondestructive evaluation of fatigue damage of ferromagnetic steels for nuclear fusion energy systems

Fusion Engineering and Design ◽

10.1016/s0920-3796(98)00180-x ◽

1998 ◽

Vol 42 (1-4) ◽

pp. 485-491 ◽

Cited By ~ 12

Author(s):

A. Gilanyi ◽

K. Morishita ◽

T. Sukegawa ◽

M. Uesaka ◽

K. Miya

Keyword(s):

Nondestructive Evaluation ◽

Fatigue Damage ◽

Nuclear Fusion ◽

Fusion Energy ◽

Energy Systems ◽

Ferromagnetic Steels

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Analytical approximations to damaged gear tooth transmission-error contributions for gear-health monitoring

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406215606930 ◽

2015 ◽

Vol 230 (7-8) ◽

pp. 1157-1182 ◽

Cited By ~ 3

Author(s):

William D Mark

Keyword(s):

Fatigue Damage ◽

Gear Tooth ◽

Transmission Error ◽

Generic Model ◽

Model Framework ◽

Bending Fatigue ◽

New Methods ◽

Analytical Approximations ◽

Significant Damage ◽

Higher Harmonic

A generic model of transmission-error contributions arising from gear-tooth damage is developed. Damage is modeled as material removed from tooth-working-surfaces. Regions of modeled tooth damage are of limited size as in pitting damage or are extended to full working surfaces as in tooth-bending-fatigue damage. Results are computed for a wide variety of damage forms and formulated for any collection of teeth experiencing damage. Final results are expressed as transmission-error rotational-harmonic amplitudes arising from damage. Rotational-harmonic regions experiencing significant damage contributions from pitting/spalling damage and from tooth-bending-fatigue damage are delineated. Increases in higher harmonic-number amplitudes arising from transmission-error discontinuities are formulated. The overall model framework can be used to explain and interpret observed features of gear transmission-error spectra arising from gear-tooth damage and to develop new methods of detecting and assessing the severity of such damage.

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