Roughness

The attached paper was recently accepted for publication in Journal of the Mechanics and Physics of Solids.

Novacam Profilometer system, for metrology and surface roughness inspection

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I am working on the surface features of steel . I understand that surface features are broken down into various wavelengths and represented as Wa to We (0.1mm to 30mm wavelengths). Could some guide me to a reference which shows how to go about this process from the raw surface profile data ? Possibly, it involves Fourier Transforms, but I need a basic reference which shows how it is done .

Thanks!

With a shallow chemical etching the roughness with spatial frequency below a critical value grows while the roughness of higher frequency decays.

node/1312

J.R.Barber

The contact of rough surfaces

Surfaces are rough on the microscopic scale, so contact is restricted to a few `actual contact areas'. If a current flows between two contacting bodies, it has to pass through these areas, causing an electrical contact resistance. The problem can be seen as analogous to a large number of people trying to get out of a hall through a small number of doors.

Classical treatments of the problem are mostly based on the approximation of the surfaces as a set of `asperities' of idealized shape. The real surfaces are represented as a statistical distribution of such asperities with height above some datum surface. However, modern measurement techniques have shown surfaces have multiscale, quasi-fractal characteristics over a wide range of length scales. This makes it difficult to decide on what scale to define the asperities.