A micromechanical model for a viscoelastic cohesive zone

A micromechanical model for a viscoelastic cohesive zone is formulated here in. Care has been taken in the construction of a physically-based continuum mechanics model of the damaged region ahead of the crack tip. The homogeni zation of the cohesive forces encountered in this region results in a damag e dependent traction-displacement law which is both single integral and int ernal variable-type. An incrementalized form of this traction-displacement law has been integrated numerically and placed within an implicit finite el ement program designed to predict crack propagation in viscoelastic media. This research concludes with several example problems on the response of th is model for various displacement boundary conditions.