CONTACT ZONE IN AN INTERFACIAL ZENER-STROH CRACK

A Zener-Stroh crack is formed by a dislocation pileup and therefore is a net dislocation loaded crack. Due to its displacement loading appro ach, only one of the two crack tips is sharp and crack propagation is possible along the sharp tip only. When a Zener-Stroh crack is initiat ed along an interface, this sharp crack tip may be closed due to mater ial mismatch and loading combination. In the present paper, an interfa cial Zener-Stroh crack is analyzed with the consideration of a crack t ip contact zone. It is found that the contact zone size which depends on the ratio of gliding dislocation and climbing dislocation can be fa irly large even when the loading is not ''shear'' dominant. (C) 1998 E lsevier Science Ltd. All rights reserved.