Experimental characterization and effect of the triaxiality on the behavior of the HDPE

Abstract

In this work, a particular interest is granted to the effect of triaxial stress states on the behaviour of the HDPE in uniaxial tensile test. To investigate this effect, tensile tests were performed using notched round bars with four different notch radii (2, 4, 10 and 80 mm). These tests were achieved on an Instron testing machine at constant strain-rate 10-3 s-1 and at ambient temperature. The measure of the local strain is done from the minimal cross-section diameter. We get then the transverse strain. The curves of behaviour deducted of these tests show that the yield stress (defined at the maximal strength point on the conventional stress-strain curve) of the material increases with the reduction of the notch radii. This tendency is due to the fact that the triaxial stress increases with the reduction of the notch radii. © Springer Science + Business Media B.V. 2009.