Micromechanical modeling of the tensile behavior of oriented polyethylene

The stacked lamellar morphology as commonly found for extruded semicrystalline materialsgives rise to a strong influence of the direction of flow with respect to the loading direction onthe stability and localization phenomena in tensile experiments. A multiscale numerical model isused to simulate the effect of a stacked lamellar microstructure on the macroscopic behavior. Themodel establishes a link between the microscopic, the mesoscopic, and the macroscopic levels.The constitutive properties of the material are identified for the crystallographic and amorphousdomains. The averaged fields of an aggregate of individual phases, having preferential orientations,form the constitutive behavior of extruded material. The microscopic morphology ofextruded HDPE material is based on WAXS experiments. The macrostructure is described by afinite element model. The microstructure-induced deformation hardening in the extrusion directionwas found to stabilize the macrostructure, when loaded in the flow direction.