The phenomenon of oscillatory necking in the stretching of polyethylene films is described. An extension of a model of Barenblatt for isothermic necking in polymers is proposed and it is shown that oscillatory necking may arise, for example, in polymers for which the effect of diffusion of stresses exceeds that of diffusion of oriented material. In such polymers, at sufficiently low temperatures, uniform necking is no longer stable and self-oscillations are observed.
ASJC Scopus subject areas
- Applied Mathematics