Analysis of acoustic emission caused by internal cracks

A calculation model for determination of acoustic emission (AE) caused by formation and subcritical growth of an internal crack in local areas near its contour is proposed. The problem is divided into the following ones: (1) instant formation in the previously loaded elastic body of a penny-shaped crack; a microcrack formation at the macrocrack front; (2) an interaction of elastic waves caused by the crack with the elastic half-space boundary and (3) the effect of a cylindrical waveguide on AE signal parameters. Using the obtained solutions the dependencies between amplitudes of AE signal and the area of subcritical crack growth are established. (C) 2001 Elsevier Science Ltd. All rights reserved.