The applicability of stripe light projection data to the determination of fractal dimensions of blast-cleaned steel surfaces

This paper is concerned with the assessment of fractal dimensions of blast-cleaned steel substrates using stripe line projection on 12 surface configurations. By means of the box-counting method and a Design of Experiment (DoE) approach, the factors abrasive type, surface preparation grade, surface roughness, and measurement direction were analyzed. The results revealed that the factor surface roughness contributed 52.5 % to the fractal dimensions. The factor measurement direction contributed 14.7 % (even up to 20 % once interactions were included) to the fractal dimension. Particularly the profile “formation” values were significantly influenced by the factor measurement direction, with contributions ranging up to 17.2 %. The potential limitations on the optical stripe light projection in capturing variations in fractal dimensions, especially in the abscissa-direction (formation), are highlighted. Whereas the box-counting method offers valuable insights, the stripe line projection introduces variations in the derived fractal dimensions. Stripe line projection shall be carefully considered when applied to fractal analysis.