CONTRIBUTION TO THE STUDY OF MECHANICAL PROPERTIES OF HIGH DENSITY POLYETHYLENE (HDPE) UNDER THE EFFECT OF TEMPERATURE AND MODELING OF ITS BEHAVIOUR AT 60 degrees C

These high density polyethylene samples (HDPE) were subject to a uniaxial tension under the influence of temperature ranging from 20 to 120 degrees C at a constant stretching speed of 50mn/mn and at various stretching speeds of 50 to 800mn/mn for a constant temperature of 60 degrees C. The material has shown various mechanical behaviors resulting in various nominal curbs. The evolution of the mechanical magnitudes has been monitored based on the two mentioned external influences. We have shown the analogy of the effect of the temperature decrease and the speed increase. In order to transform the nominal curbs into true curves, we have assumed a relation whose implementation has given a good compliance with the bibliographical research. By selecting the curve achieved a 60 degrees C for a stretching speed of 50mn/mn with the assumption that the polymer is isotropic, the plain deformation homogenous perfect plastic and for a triaxibility coefficient F-T = 1,0877; the implementation of Von Mises relations has allowed us to complete an effective curb. The latter has given a good compliance with the multiplicative curve, modeled according the G'SELL law,