THE INFLUENCE OF CUT-OFF WAVELENGTH FOR ROUGHNESS AND SAMPLING WAVELENGTH FOR ELIMINATING NOISE ON 3D AMPLITUDE PARAMETERS

2024-12-03T22:59:50+02:00

This paper presents arguments in the favor of selecting the adequate set of filters λc (cut-off wavelength for roughness) and λs (sampling wavelength for eliminating noise), in studying the 3D amplitude parameters, including average arithmetic deviation of the surface (Sa), Ssk, Sku, Sq, Sv, Sp, St. This analysis was carried out for a surface of 1000 µm x1000 µm, from a ball made of chrome steel, with a diameter of 12.7 mm ± 0.0005 mm, which, according to the ISO standard 683-17:2023, they are finely grinded and have a high hardness (62...65 HRC) and a high quality surface. The authors present an analysis for 3D amplitude parameters, for the same surface, but after applying different pair of filtering (λs, λc) and discussed their influence on the values of amplitude parameters. For Sa, standard deviation of values obtained at the same λc, but for λs=0.8-250 µm, is decreasing to a lower value only for λc = 100-250 µm, but values increase from nanometers to higher average value (3.59 µm for λc=900 µm). Similar tendency was noticed for Sq. Ssk and Sku have revealed a convergence towards the largest value of λc, meaning that λs has no significant influence when the cut-off length is almost the dimension of the investigated area, at least for λs=0.8-250 µm. St decreases with the increasing of λs, but it increases with the increases of λc. A larger λs is favorable to avoid recording the deepest valley. It is important to report the λc and λs values as they have directly impact on roughness values (as demonstrate here for 3D amplitrude parameters, like Sa, Sq etc.).
This study and the cited references evidence that different settings can produce different results for the same surface. Including them in the report ensures transparency and reproducibility.

Mechanical Testing and Diagnosis

THE INFLUENCE OF CUT-OFF WAVELENGTH FOR ROUGHNESS AND SAMPLING WAVELENGTH FOR ELIMINATING NOISE ON 3D AMPLITUDE PARAMETERS