Next Article in Journal
Effect of Anode Pulse-Width on the Microstructure and Wear Resistance of Microarc Oxidation Coatings
Next Article in Special Issue
RBF-Neural Network Applied to the Quality Classification of Tempered 100Cr6 Steel Cams by the Multi-Frequency Nondestructive Eddy Current Testing
Previous Article in Journal
Separation and Pre-Concentration of Pb and Cd in Water Samples Using 3-(2-hydroxyphenyl)-1H-1,2,4-triazole-5(4H)-thione (HTT) and Their Determination by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES)
Open AccessArticle

Acoustic Emission Signatures of Fatigue Damage in Idealized Bevel Gear Spline for Localized Sensing

Civil and Materials Engineering, University of Illinois at Chicago, Chicago, IL 60607, USA
Naval Air Systems Command (NAVAIR), Patuxent River, MD 20670, USA
Author to whom correspondence should be addressed.
Metals 2017, 7(7), 242;
Received: 30 May 2017 / Revised: 26 June 2017 / Accepted: 26 June 2017 / Published: 30 June 2017
(This article belongs to the Special Issue Advanced Non-Destructive Testing in Steels)
In many rotating machinery applications, such as helicopters, the splines of an externally-splined steel shaft that emerges from the gearbox engage with the reverse geometry of an internally splined driven shaft for the delivery of power. The splined section of the shaft is a critical and non-redundant element which is prone to cracking due to complex loading conditions. Thus, early detection of flaws is required to prevent catastrophic failures. The acoustic emission (AE) method is a direct way of detecting such active flaws, but its application to detect flaws in a splined shaft in a gearbox is difficult due to the interference of background noise and uncertainty about the effects of the wave propagation path on the received AE signature. Here, to model how AE may detect fault propagation in a hollow cylindrical splined shaft, the splined section is essentially unrolled into a metal plate of the same thickness as the cylinder wall. Spline ridges are cut into this plate, a through-notch is cut perpendicular to the spline to model fatigue crack initiation, and tensile cyclic loading is applied parallel to the spline to propagate the crack. In this paper, the new piezoelectric sensor array is introduced with the purpose of placing them within the gearbox to minimize the wave propagation path. The fatigue crack growth of a notched and flattened gearbox spline component is monitored using a new piezoelectric sensor array and conventional sensors in a laboratory environment with the purpose of developing source models and testing the new sensor performance. The AE data is continuously collected together with strain gauges strategically positioned on the structure. A significant amount of continuous emission due to the plastic deformation accompanied with the crack growth is observed. The frequency spectra of continuous emissions and burst emissions are compared to understand the differences of plastic deformation and sudden crack jump. The correlation of the cumulative AE events at the notch tip and the strain data is used to predict crack growth. The performance of the new sensor array is compared with the conventional AE sensors in terms of signal to noise ratio and the ability to detect fatigue cracking. View Full-Text
Keywords: fatigue testing; acoustic emission; spline; gearbox; sensor array fatigue testing; acoustic emission; spline; gearbox; sensor array
Show Figures

Figure 1

MDPI and ACS Style

Zhang, L.; Ozevin, D.; Hardman, W.; Timmons, A. Acoustic Emission Signatures of Fatigue Damage in Idealized Bevel Gear Spline for Localized Sensing. Metals 2017, 7, 242.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Search more from Scilit
Back to TopTop