THE CREEP MASTER CURVE GONSTRUCTION FOR THE POLYAMIDE 6 BY THE STEPPED ISOSTRESS METHOD

Abstract

The creep test allows the prediction of the viscoelastic materials tendency to deform undor constant loading; however, this test requires a very long testing time. The application of the time-stress superposition principle (TSSP) provides the prediction of the material performance extensively beyond the creep test time. A new accelerated creep testing technic, called the stepped isostress method (SSM), was recently proposed. It requires specific processing method of the test data in order to conskuct the creep master curye. Initially this method was used on geosynthetics yarns. This paper focuses on the effectiveness of this method to predict the long term creep behavior of thick thermoplastic specimen made from polyamide 6. The different processing steps of the SSM technic are illustrated in this paper. A smooth master curve is conskucted and the long term material performance is predicted over a very long period. It is found that, the creep master curve based on SSM technic agfees perfectly with that based on the classical TSSP method.