Study of contact mechanics between two brass solids in various diameter ratios and friction coefficient

Abstract

Contact mechanics is the study of the behavior of solids when they come into contact at one or more points. Contact mechanics research allows for the investigation of tribology, contact stiffness, electrical contact resistance, and indentation hardness. This understanding is required for the safe and efficient design of technological systems. One of the main interesting research observations is the study of contact mechanics behavior between two brass hemisphere with different diameter ratios and friction coefficients, which subsequently becomes the subject of this study. For this study, seven diameter ratios ranging from one- to seven-folds were compared using friction coefficients of 0.05, 0.1, 0.4, and 0.8. Both experiments and simulations were performed to investigate the behavior of the contact mechanics. The experiments and simulation were designed to investigate the effect of friction coefficient and diameter ratio on Von-Misses in the loading process and deformation. The results of the finite element method simulations µ = 0 and lubricated condition experiments are coherent between each other. As a result, it is proven that the coefficient of friction has influenced the unloading deformation and von Mises stress distribution. However, the impact on the deformation ratio with a coefficient of friction from 0.05 to 0.8 does not show a significant difference. The distribution of von Mises stress on diameter ratio 1 showed similar results between the two specimens. Specimen 2 had a wider von Mises stress distribution than specimen 1 at a higher diameter ratio. From diameter ratio 3 to diameter ratio 7, there is a highly localized stress at the edge of the contact area. This region is caused by shear stress as a result of the middle material pushing the surrounding material sideways. When the friction coefficient is increased, the localized stress area decreases, which indicates that the resultant load given is reduced.