On the Distribution of Pressed Surface Profiles (3rd Report) : On Numbers of Contact-Points Estimated by the Distribution of Quartiles

Abstract

We considered the numbers and size of elementary area of contact-points, applying the distribution of quartiles to the observed distribution of stable positions of a flat indenter on the metal surface. Namely, we measured the fluctuation of the indenter setting on the metal step by step, and obtained a good agreement between the observed and theoretical results. So we estimated the numbers and unit area of contact-points by the contained. parameter 'sampling size' of the distribution function of quartiles. Our results are found at the mean value of results by the electric resistance and optical methods. For expample, by a mild steel and a block-gauge under mean pressure=1kg/mm² and the appearance of contact-area=0.5mm², we obtain 18 points and (9×9)μ² area of contact.