Some considerations of crazing of polymers: Twohyphen;dimensional quasifracture of polymers

摘要

In a tensile stress field, certain polymeric solids deform and develop quasifracture formations. Each such formation is termed a craze. Previous analyses by Knight and Lauterwasser and Kramer have treated a craze by introducing either an assumed or a measured displacement field for the calculation of the stress distribution around the craze profile. In this paper the new phase of oriented polymer molecular bundles within the craze profile has been considered through the use of a linear modulus function for those bundles. Both displacement and stress fields have been calculated. This model developed for studying planar crack has its limitations when it is used for craze investigations. The basic model treatment depends upon classical linear fracture mechanics which is not valid for materials with a zone of craze occurrence. In addition, anisotropic and nonlinear as well as time dependent considerations are difficult to be incorporated into the model analysis.