A numerical study of geometric and material instability in uniaxial drawn polymers

Abstract

In this study, the general purpose Finite Element Code, ABAQUS, with a non-linear solution has been employed to study the neck profile in drawn polymers. Attempts are made to obtain the relationship between the neck profile, neck propagation and uniaxial stress-strain behaviour of the polymers. Finite element analyses are carried out for destabilised polyvinyl chloride (uPVC), high-density polyethylene (HDPE), polypropylene (grades GSE108 and GSE16 ICI) and model uniaxial stress-strain behaviour. The results show a close relationship between the neck profile and the draw ratio and strain rate in the neck, that are related to the material, test speed and specimen geometry. Finally, the capability of the finite element technique in the prediction of the polymer stress-strain-strain-rate surface is discussed. Copyright (C) 1996 Elsevier Science Ltd