Polymer, Vol.35, No.7, 1442-1451, 1994
Finite-Element Analysis of Single-Edge-Cracked Rolled High-Density Polyethylene
Stress and strain distributions around the crack tip of rolled high-density polyethylene have been analysed using the two-dimensional finite element method. Mechanical parameters from two samples were used. The highly anisotropic sample showed distinct differences in Young’s moduli and yield stresses versus various off-axis angles while the sample of low anisotropy showed high moduli and yield stresses in both the roll and the transverse direction. Calculated results revealed a strong relation between the stress distributions at the crack front and the anisotropy of the materials. The sample with high anisotropy showed intense stress distributions coincident with the chain axis. In contrast, stress distributions of the sample with low mechanical anisotropy were less affected by the alignment of the chain axis. From experiment, kinky deformation was observed for some cases. Comparison of the experimental with the calculated results threw light on the mechanism of formation of a kink band during restretching of anisotropic polymers.
Keywords:MOLECULAR-WEIGHT