Tadej Kosel, Igor Grabec and Franc Kosel
In Part I, an intelligent acoustic emission (AE) locator is described while the Part II discusses a blind source separation, time delay estimation and location of two continuous…
Abstract
In Part I, an intelligent acoustic emission (AE) locator is described while the Part II discusses a blind source separation, time delay estimation and location of two continuous AE sources. AE analysis is used for characterization and location of developing defects in materials. AE sources often generate a mixture of various statistically independent signals. A difficult problem of AE analysis is a separation and characterization of signal components when the signals from various sources and the mode of mixing are unknown. Recently, blind source separation (BSS) by independent component analysis (ICA) has been used to solve these problems. The purpose of this paper is to demonstrate the applicability of ICA to locate two independent simultaneously active AE sources on an aluminum band specimen. The method is promising for non‐destructive testing of aircraft frame structures by AE analysis.
Acoustic emission analysis (AE) is used for characterization and location of developing defects in materials. AE sources often generate a mixture of various statistically…
Abstract
Acoustic emission analysis (AE) is used for characterization and location of developing defects in materials. AE sources often generate a mixture of various statistically independent signals. One difficult problem of AE analysis is the separation and characterization of signal components when the signals from various sources and the way in which the signals were mixed are unknown. Recently, blind source separation (BSS) by independent component analysis (ICA) has been used to solve these problems. The main purpose of this paper is to demonstrate the applicability of ICA to time‐delay estimation of two independent continuous AE sources on an aluminum beam. It is shown that it is possible to estimate time delays by ICA, and thus to locate two independent simultaneously emitted sources.
Details
Keywords
Tadej Kosel, Igor Grabec and Franc Kosel
The intelligent acoustic emission (AE) locator is described in Part I while Part II discusses a blind source separation, time delay estimation and location of two simultaneously…
Abstract
The intelligent acoustic emission (AE) locator is described in Part I while Part II discusses a blind source separation, time delay estimation and location of two simultaneously active continuous AE sources. Location of AE on complicated aircraft frame structures is a difficult problem of non‐destructive testing. In this article an intelligent AE source locator is described. The intelligent locator is comprised of a sensor antenna and a general regression neural network, that solves the location problem based on learning from examples. The locator performance was tested on different test specimens. The tests have shown that accuracy of location depends on sound velocity and attenuation in the specimen, the dimensions of tested area, and properties of stored data. The location accuracy achieved by the intelligent locator is comparable to that obtained by the conventional triangulation method. This is a promising method for non‐destructive testing by AE method of aircraft frame structures.