Finite element analysis and experimental validation of polymer–metal contacts in block-on-ring configuration

Abstract

The wear profile analysis, obtained by different tribometers, is essential to characterise the wear mechanisms. However, most of the available methods did not take the stress distribution over the wear profile in consideration, which causes inaccurate analysis. In this study, the wear profile of polymer–metal contact, obtained by block-on-ring configuration under dry sliding conditions, was analysed using finite element modelling (FEM) and experimental investigation. Archard’s wear equation was integrated into a developed FORTRAN–UMESHMOTION code linked with Abaqus software. A varying wear coefficient (k) values covering both running-in and steady state regions, and a range of applied loads involving both mild and severe wear regions were measured and implemented in the FEM. The FEM was in good agreement with the experiments. The model reproduced the stress distribution profiles under variable testing conditions, while their values were affected by the sliding direction and maximum wear depth (h_max). The largest area of the wear profile, exposed to the average contact stresses, is defined as the normal zone. Whereas the critical zones were characterized by high stress concentrations reaching up to 10 times of that at the normal zone. The wear profile was mapped to identify the critical zone where the stress concentration is the key point in this definition. The surface features were examined in different regions using scanning electron microscope (SEM). Ultimately, SEM analysis showed severer damage features in the critical zone than that in the normal zone as proven by FEM. However, the literature data presented and considered the wear features the same at any point of the wear profile. In this study, the normal zone was determined at a stress value of about 0.5 MPa, whereas the critical zone was at about 5.5 MPa. The wear behaviour of these two zones showed totally different features from one another.