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.

本文的目的是使用实验和基于微观力学的建模相结合的方法研究应力三轴性如何影响高密度聚乙烯的塑性变形行为。为了在中间截面中设置不同的三轴应力状态，在具有不同曲率半径的沙漏形拉伸试样的良好控制的横向响应下，通过实验量化应力-应变行为以及空化损伤累积。然后在基于连续介质的微机械框架内呈现本构弹塑性损伤表示。该模型受与实验测试相同的边界条件约束，