Two-scale fractal method for characterization of worn surfaces from internal combustion engine cylinder bores

Despite the importance of wear characterization of cylinder bores, the multiscale nature of wear demands scale-invariant analyzes at different scales. In this work, a two-scale fractal method for characterization of worn surfaces from cylinder bores is proposed. The method is applied to investigate the effects of wear at plateau roughness and honing grooves scales from cylinder bores from an engine after 100 h dynamometer test. The two-scale fractal method presented strong correlation with wear, indicating that the analysis of the largest and the smallest scales of roughness from cylinder bores is enough to analyze surface changes due to wear at asperity level. Contact mechanics and friction models for cylinder bore/piston ring tribosystems can also benefit from the proposed method.