Optimisation-oriented verification of a plain bearing process model taking into account actual tolerances and measurement accuracy

This paper presents a methodology for verifying a numerical model of the plain bearing test process used to evaluate the characteristics of internal combustion engine components, in particular camshaft bearings. The developed approach is based on the use of optimisation methods under parametric uncertainty, which makes it possible to take into account the actual spread of technological and operational parameters. The study uses a test rig that reflects the operating conditions of a bearing in an internal combustion engine, including a load simulated with an eccentric. SAE 15W40 grade oil, typical for engine lubrication systems, was used as the lubricant. The input parameter space includes geometrical features of the bearing (diameter, width, clearance, eccentric), initial load force, shaft speed and rheological properties of the oil. The proposed approach to verification does not involve a direct comparison of computational and experimental data, but rather a search for the most probable solution within given tolerance limits and taking into account the measurement accuracy of the selected characteristics. The verification criteria are the measured values of oil and bearing surface temperature, load force and friction torque in the oil film. Measurement uncertainty is also taken into account in the optimisation process. The developed methodology makes it possible not only to assess the reliability of the numerical model, but also to analyse the sensitivity of the model to parameter variability and to determine the robustness of the friction node under study.