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Normal displacements in non-Coulomb friction conditions during fretting

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Original languageEnglish
Pages (from-to)633-639
JournalTribology International
Early online date1 Nov 2015
Publication statusPublished - 2016
Publication typeA1 Journal article-refereed


Non-Coulomb friction may occur in gross sliding fretting conditions, in which the tangential force increases as the fretting movement approaches its extreme position and produces 'hooked' fretting loops. Uncertainties in frictional behaviour make the design of highly loaded contacts against fretting a challenging task. Experiments were made with quenched and tempered steel, and cyclic normal displacements were discovered during non-Coulomb friction conditions. Normal displacement and non-Coulomb friction were caused by tangential fretting scar interactions between protrusions and depressions formed by material transfer. Tangential interlocking leads to inclined sliding conditions, which produce loading components in both tangential and normal directions; this explains most non-Coulomb friction.


  • Fretting, Friction, Wear

Publication forum classification

Field of science, Statistics Finland