Acoustic emission and near-tip elastodynamic fields of a growing penny-shaped crack

Abstract

Elastodynamic fields for a growing penny-shaped crack under tension have been obtained by the time-domain boundary integral equation method. A crack of radius R 1 , is initially in equilibrium with a static tensile stress applied at infinity. The crack then propagates with a given rupture velocity, but stops abruptly when its radius reaches R 2(> R 1) . Numerical results have been calculated for various values of the rupture velocity and the initial radius, R 1 , of the crack. Crack-opening displacements, stress intensity factors and radiated far fields are graphically presented as functions of time. The acoustic emission in terms of the radial displacement as calculated in this paper, has been compared with the usual approximation in which the acoustic emission is generated by a system of three double forces whose magnitudes are proportional to the crack-opening volume.