In Geotechnical engineering  the term asperity is mostly used for unevenness (roughness) of the surface of a discontinuity, grain, or particle with heights in the range from approximately 0.1 mm to the order of metres. Smaller unevenness is normally considered to be a material property (often denoted by material friction, atomic friction or molecular friction).
In Geotechnical engineering and contact mechanics the term asperity is used to refer to individual features of unevenness (roughness) of the surface of a discontinuity, grain, or particle with heights in the range from approximately 0.1 mm to the order of metres. Below the asperity level, surface interactions are normally considered to be a material property , arising from mechanisms of adhesion and repulsion at the atomic scale (often accounted for by material friction, atomic friction or molecular friction).
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and contact mechanics
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mostly used for
used to refer to individual features of
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Smaller unevenness is
Below the asperity level, surface interactions are
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(often denoted
, arising from mechanisms of adhesion and repulsion at the atomic scale (often accounted for