Orthogonal Simulation Test for Evaluating Fretting Wear in Low-Speed Diesel Engine Connecting Rods

Fretting wear primarily impacts the bushing of the con-rod, subsequently influencing the con-rod's overall performance. In this investigation, the contact interactions between the con-rod small end, the small end cover, and the bushing under conditions of utmost combustion pressure were investigated. This analysis included examining the contact pressure and friction stress distribution. Subsequently, an orthogonal simulation test was developed to further investigate these interactions. The study took into account the friction coefficient of the interface and the quantity of interference as test factors based on contact mechanics theory. The objective functions were the utmost friction stress and contact pressure, ascertained under conditions of peak combustion pressure. Based on the findings from this study, the contact pressure of the top portion of the bushing is lower than that of the bottom portion. The friction stress of the top portion of the bushing is larger than that of the bottom portion. The optimal values for the interference amount and friction coefficient are 0.11 and 0.15, respectively, which will result in the most favorable conditions for minimizing fretting wear in the bushing.