Characterization of interfacial shear strength and its effect on ploughing behaviour in single-asperity sliding

The shear strength at the interface contributes to the overall friction force experienced by the contacting bodies sliding against each other. In this article, an experimental technique to characterize the shear strength at the interface of metallic bodies in sliding contact has been developed. The boundary layers formed at interface in a lubricating contact have been varied by using two different types of lubricants in combination with both zinc coated and uncoated steel sheets. The empirical relations between the experimental parameters such as contact pressure and sliding velocity and the interfacial shear strength have been expressed by fitting the experimental results. These expressions have been incorporated in the Material Point Method (MPM) based ploughing model. The coefficient of friction and ploughing depth obtained from the numerical simulations have been validated relative to the experimental results with a good agreement for both lubricated and unlubricated substrates, different loads and spherical indenter sizes. Furthermore, the interfacial shear strength has been varied in the MPM-based ploughing model and ploughing experiments to study the contribution of interfacial shear strength to overall friction, deformation and wear. •An experimental characterization technique of interfacial shear strength from the measured friction force and the contact area in line contact loading on coated sheet metals is developed.•The interface is varied using zinc coated and uncoated steel sheets, with different surface roughness and conditions, with or without using one of the two given lubricants.•The interfacial shear strength is measured and plotted for different interfaces over a range of contact pressures and sliding velocities and curve-fitted to mathematical relations.•The shear strength relations are included in the MPM-ploughing model whose results are compared with ploughing experiments on steel sheets for varying interfaces and applied loads.•The effects of varying interfacial shear strength on ploughing friction, substrate deformation and abrasive wear are studied using the MPM-ploughing model and ploughing experiments.