Wavelet transform is a well-known signal processing technique which has proven to be a successful technique in Non-Destructive Testing (NDT). Adopting this technique by Acoustic Emission (AE) method could result in better interpretation of data that are used for fault detection. In this study, AE signals emitted from automobile engines in both faulty and healthy conditions are analyzed using wa...

Acoustic emission (AE) sensors have been fabricated using both soft- and hard-type lead-free (Na0.5K0.5)NbO3-based ceramics. The acoustic and electromechanical properties of the ceramics have been determined using the resonance technique. The lead-free AE sensors were calibrated using a laser source and compared to a commercial sensor. A lead zirconate titanate (PZT) 5H ceramics AE sensor has a...

Acoustic emission transducers were used to study the brush/rotor interface of a homopolar motor as a function of design parameters such as speed and load. The results indicate that acoustic emission is well suited for in situ monitoring of brush wear and rotor conditions, and for analyzing the tribological phenomena occurring at the brush/rotor interface. r 2007 Elsevier Ltd. All rights reserved.

We study acoustic emission avalanches during the process of failure of porous alumina samples (Al2O3) under compression. Specimens with different porosities ranging from 30% to 59% have been synthesized from a mixture of fine-grained alumina and graphite. The compressive strength as well as the characteristics of the acoustic activity have been determined. The statistical analysis of the record...

Due to the extensive use of composites in various industries and the fact that defects reduce ultimate strength and efficiency during operation, detection of failures in composite parts is very important. The aim of this paper is to use Acoustic Emission (AE) non-destructive method in four-point bending test of carbon/epoxy composite to analyze and examine the failure mechanisms. This method is...

Acoustic emission (AE) is one of the most recent entries into the field of nondestructive evaluation. Due to the uniqueness of the basic principle and the potential for tackling a wide range of applications, the technique has gone through rapid strides in a very short time. Thus, today, two decades after the first application of the technique, AE is used in various industries, such as petro-che...

In this paper acoustic transmitters that were developed for use in underwater neutrino telescopes are presented. Firstly, an acoustic transceiver has been developed as part of the acoustic positioning system of neutrino telescopes. These infrastructures are not completely rigid and require a positioning system in order to monitor the position of the optical sensors which move due to sea current...

One of the important features of the racing car is the power to weight ratio, and to this end, weight has been considerably reduced by the use of carbon fibre in the modern Formula One car. The weight saving obtained from carbon fibre components is utilised by the strategic placement of ballast (since there is a minimum weight limit set by the racing authority, the FIA), ordinarily as low as po...