Deformational behavior of Polyolefins at High Temperature and Strain Rate: Experimental Analysis and Constitutive Laws

Large deformation behavior of two poliolefins has been investigated under high temperatures and high strain rate conditions. During uniaxial tensile tests at constant true strain rate, volume, stress, and deformation ratio were measured. At the temperatures considered, the mechanical behavior tends to be elastic (rate independent) as strain rate increases. Thus elastic models can be used to describe the deformational behavior of these resins under such conditions. Models proposed by Ogden, by Coleman as modified by Radi and by Sweeney-Ward have been considered to fit experimental data and their adequacy has been discussed. Sweeney-Ward's model has been found to provide the best fit of the examined polymer's behavior at high temperatures and high strain rates.