FINITE-ELEMENT MODEL AND EXPERIMENTAL-ANALYSIS OF CRACK-INCLUSION INTERACTION

One of the key requirements for developing tough multiphase blend systems, for example, selecting the type of discrete phases (hard or soft) in a polymer matrix, is the ability to predict the fracture path. Most of these selections rely heavily on prior experience or on intuitive rationale. There are few mathematical guidelines for the materials scientists who are designing new multiphase systems. This article is designed mainly to provide such insight through the development of a theoretical model and through experimental observation. A finite element model has been used to predict the crack velocity and the crack path for a crack that approaches and penetrates a hard or a soft inclusion. A novel experimental approach is then utilized to verify these predictions by introducing hard and soft circular domains in poly(ethylene-co-carbon monoxide) specimens by selective photodegradation. (C) 1993 John Wiley & Sons, Inc.