TRANSONIC CRACK-GROWTH ALONG A BIMATERIAL INTERFACE - AN INVESTIGATION OF THE ASYMPTOTIC STRUCTURE OF NEAR-TIP FIELDS

Transonic interfacial crack growth in bimaterial systems is analysed, and the asymptotic field around the moving crack tip is obtained by th e straightforward approach of analytic continuation. The power of sing ularity is less than 1/2 for anti-plane shear deformation. For in-plan e deformation, the power of singularity can be real or complex, depend ing on the speed of the crack tip. Across the Rayleigh wave speed, the real part of the power has a jump of - 1/2, and the imaginary part ap proaches infinity. The stresses are singular, not only around the crac k lip, but also on an entire ray moving with the crack tip. These obse rvations are illustrated by examples using PMMA/steel and Al/Al2O3 bim aterial systems. Copyright (C) 1996 Published by Elsevier Science Ltd.