Expansion of the Metrological Visualization Capability by the Implementation of Acoustic Emission Analysis

The acquisition and evaluation of acoustic emissions (AE) in tribology have proven to be a meaningful tool for condition monitoring and offer possibilities to deepen the understanding of tribological processes. The authors used this technology with the aim of expanding existing test methodologies towards increased visualization capability of tribological processes and investigated the correlation between tribological processes and acoustic emissions on a Ring-on-Disc and a close-to-component journal bearing test setting. The results of this study include the description of friction as well as wear processes and prove the usability of several AE evaluation parameters whereby a close correlation between AE and tribological processes can be shown. Consequently, it was possible to expand the visualization and evaluation capabilities of the test settings offering additional insights by making use of AE.

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Acoustic emission analysis for bearing condition monitoring

Wear ◽

10.1016/0043-1648(95)06591-1 ◽

1995 ◽

Vol 185 (1-2) ◽

pp. 67-74 ◽

Cited By ~ 51

Author(s):

C. James Li ◽

S.Y. Li

Keyword(s):

Acoustic Emission ◽

Condition Monitoring ◽

Emission Analysis ◽

Bearing Condition Monitoring ◽

Acoustic Emission Analysis

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Scalable Monitoring System for the Localization of Damaging Events in Thin-Walled CFRP Structures Based on Acoustic Emission Analysis and Neural Networks

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.809.401 ◽

2019 ◽

Vol 809 ◽

pp. 401-406

Author(s):

Benjamin Kelkel ◽

Philipp Argus ◽

Martin Gurka

Keyword(s):

Acoustic Emission ◽

Acoustic Waves ◽

Structural Integrity ◽

Low Cost ◽

Acoustic Emissions ◽

Variable Component ◽

Emission Analysis ◽

Thin Walled ◽

Primary Structures ◽

Acoustic Emission Analysis

A constant challenge for the design and operation of CFRP primary structures is their sensitivity towards impact loading. This can lead to the formation of externally invisible delaminations which endanger the structural integrity. In practice, this circumstance is encountered with elaborate inspections or conservative design. Structural Heath Monitoring (SHM) systems offer the potential for permanent monitoring and represent an alternative approach that has drawn more attention in the last decade. The biggest barriers to market entry for this technology are system costs and reliability. This study is dedicated to these two points with the development of a low-cost system with which representative acoustic emission sources can be located reliably in a complex CFRP structure. The implementation is carried out using acoustic emission analysis, which represents a promising solution for the integral monitoring of primary structures. It is based on the detection of acoustic waves that are released during crack initiation and growth and propagate over large areas in thin-walled structures as Lamb waves. The challenges of source localization in thin-walled CFRP structures lie in the consideration of wave dispersion, anisotropic material properties, variable component geometry and interfaces. In this thesis, this complexity is captured by training a neural network. For this purpose, artificial sources are used which imitate acoustic emissions of typical damaging events in the material in frequency and mode content. The demonstrating component is an omega profile equipped with a network of piezoelectric sensors that is designed for reliable localization within a defined window. Signal processing takes place on a single-board computer which, together with a digital oscilloscope, completes the measurement chain. The system represents a modular, low-cost approach that can be transferred to other applications by adapting the hardware and training.

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