Use of equivalent body forces for acoustic emission from a crack in a plate. (September 2015)

• Record Type: Journal Article
• Authors: Zhang, Han; Achenbach, Jan D.
• Is Part Of: Mechanics research communications. Volume 68(2015:Sep.)
• Page Start: 105
• Page End: 108
• Publication Date: 2015-09
• Subjects: Crack -- Acoustic emission -- Surface waves -- Equivalent body forces; Mechanics, Applied -- Periodicals; Mécanique appliquée -- Périodiques; Mechanics, Applied; Periodicals; 530
• DOI: 10.1016/j.mechrescom.2015.04.002
• Languages: English
• ISSNs: 0093-6413

Abstract

Highlights: Acoustic emission of surface waves by a sub-surface crack in a plate. Use of elastodynamic reciprocity theorem to determine the amplitude of the emitted wave. Result obtained in time domain, in terms of the crack-opening time function. Abstract: A method to determine acoustic emission of surface waves from a crack near the free edge of a plate, is presented, in terms of the function f ( t ), which defines the time dependence of the crack opening process, the crack opening volume per unit thickness of the plate, and the elastic constants of the plate. The determination of the time-varying displacement is based on the use of equivalent body forces, which are shown to be two double forces. The acoustic emission of the crack, or the equivalent radiation from the double forces, has been obtained by a novel use of the elastodynamic reciprocity theorem. It is of interest that the normal surface-wave displacement at a position x 0 of the free edge comes out as depending on d f/ d t evaluated at x 0 for t > x 0 / c R, where c R is the velocity of surface waves on the free edge.