Investigation and measurement of the true stress/strain behaviour of semi-crystalline thermoplastics

Abstract

In this paper the differences are examined between the true and the technical stress/strain behaviour of thermoplastics. Investigations of the true material behaviour are needed because thermoplastics are being increasingly used as materials for components that are subject to plastic strains. In order to the able to dscribe these strains as exact as possible, a knowledge of the true stress/strain behaviour is of major importance, and this behaviour must be established experimentally. Among other things, this paper examines the influence that the type of control systems in the testing machines will have on the results, so that conclusions can be drawn regarding the amount of technical equipment required.