How Stress Triaxiality Affects Cavitation Damage In High-Density Polyethylene: Experiments And Constitutive Modeling

The aim of this article is to investigate how the stress triaxiality affects the plastic deformation behavior of high-density polyethylene using an approach combining experiments and micromechanics-based modeling. The stress-strain behavior along with the cavitation damage accumulation are experimentally quantified under well-controlled transversal response of hourglass-shaped tensile specimens with different curvature radii in order to set different triaxial stress states in the median cross-section. A constitutive elastic-plastic-damage representation is then presented within a continuum-based micromechanical framework. The model, constrained by the same boundary conditions as the experimental tests, is used to examine the stress triaxiality effects on the separate and synergistic effects of plasticity and cavitation damage micromechanisms that govern the macro-response.