Elastic Wave Scattering by Surface-Breaking Planar and Nonplanar Cracks

摘要

Problems of elastic wave scattering by surface-breaking and near-surface cracks are of considerable current interest for ultrasonic nondestructive evaluation. Ultrasonic scattering by planar cracks near or at the free surface of a semi-infinite elastic homogeneous medium has been studied theoretically by many authors. Ultrasonic scattering by surface-breaking planar and branched cracks of arbitrary orientation is the subject of this investigation. To our knowledge this problem has not received much attention in the literature. An approximate solution that is valid at low frequencies was presented by Datta(1979)for SH wave diffraction by a canted surface-breaking planar crack. Subsequently, a hybrid finite element and eigenfunction technique was used by Datta et al.(1982)to study SH wave diffraction by a planar surface-breaking canted crack. Reprints. (jes)