2026-10-12T15:00:56Z https://www.scidb.cn/oai

10.57760/sciencedb.Tribology.00013 2026-06-16T09:36:10Z

2026-06-16 Elastoplastic Fretting Contact Analysis of Piston Crown-Skirt Joint Surface base on BEM-FEM coupling Method doi:10.57760/sciencedb.tribology.00013 en This research investigates the elastoplastic fretting contact behavior of the rough surfaces at the piston crown-skirt joint in marine diesel engines. A coupled Boundary Element Method-Finite Element Method (BEM-FEM) model, which integrates Fast Fourier Transform (FFT) and Conjugate Gradient Method (CGM), has been developed to serve as a tool for optimizing piston design and enhancing reliability under actual operating conditions. Unlike traditional analyses of smooth surfaces, this study accounts for actual surface roughness, thereby providing a more accurate representation of contact status. The BEM-FEM model effectively combines the computational efficiency of boundary elements with the detailed modeling of material behavior afforded by finite elements. The study simulates the working forces acting on the piston assembly, including combustion pressure, inertia, and lateral forces, to analyze the interactions between the piston crown and skirt. An entire engine cycle is simulated to elucidate the evolution of contact states under realistic loads. At the top dead center (0°crank angle), the maximum axial load results in elevated contact pressure and minimal slip. In contrast, at a crank angle of 315°, lateral forces become predominant, leading to increased shear stress and the slip regions. During the downward stroke, as combustion pressure diminishes and inertia forces prevail, contact pressure decreases, thereby reducing the overall contact area. This phase is particularly susceptible to fretting damage due to the diminished normal force, which facilitates micro-slips between the contact surfaces. The increased variability in shear stress during this phase suggests a potential for slip and the initiation of fretting damage. These findings underscore the necessity of optimizing preload force and taper angle to enhance stability and mitigate wear.The study also incorporates varying preload forces and taper angles to assess their impacts on contact pressure, tangential shear stress, and stick-slip behavior. The results indicate that reducing the taper angle from 0.25° to 0° improves the distribution of contact pressure, minimizes slip zones, and increases stable contact areas. Additionally, an increase in preload force correlates with a reduction in slip, with near-complete elimination observed at a preload of 2000 N. These findings suggest that optimizing taper angle and preload force can significantly enhance the performance of the piston crown-skirt joint, thereby reducing fretting wear and prolonging component lifespan. piston crown-skirt joint; fretting; elastoplastic contact; fast fourier transformation; conjugate gradient method; rough surface Li Liting Tang Yihu Guang-Yao Ouyang Meng Xianghui PUBLIC https://creativecommons.org/licenses/by-nc-nd/4.0/ dataset Science Data Bank