Elastic contact stress analysis of semi‐crystalline polymers under normal and tangential loading

Publisher Website
Google Scholar
Abstract
Stress distribution in a polymeric subsurface under the asperity contact is investigated assuming the well known Hertzian contact stress distribution. Elastic stress analyses for three different materials are performed using a finite element method: (1) isotropic elastic solid, (2) isotropic elastic solid with a soft layer, and (3) isotropic elastic solid with a hard layer. Highly linear polymers as high density polyethylene (HDPE), poly(tetrafluoroethylene) (PTFE), and polyoxymethylene (POM) which transfer thin wear films are modeled as the elastic solid with a soft layer. Gammaray irradiated highly linear polymers and the other ordinary semi‐crystalline polymers which transfer massive lumpy wear debris are considered as the elastic solid without any heterogeneous surface layer. Helium plasma treated polymers are modeled as the elastic solid with a hard layer. Octahedral shear stress and equivalent strain contours in the subsurface are obtained for each case. The octahedral shear stress and equivalent strain distributions are examined to explain various wear behaviors of semicrystalline polymers based on the Mises yield criterion and the delamination theory of wear.