FRETTING FATIGUE IN ELASTIC CONTACTS DUE TO TANGENTIAL MICROMOTION

Stress analysis of two elastic bodies in contact, when one of them is subjected to an alternating stress, was carried out in this study. Sur face and effective stresses for different values of applied alternatin g stress were determined within the area of contact. Critical zones wh ere fretting fatigue cracks may initiate were found at the edge of con tact where stresses reach a maximum. Displacement distribution due to various types of stresses was determined and was found to increase wit h increasing the applied alternating stress and the distance from the centre of contact. An expression to predict fatigue failure under fret ting conditions was proposed. This expression includes most parameters which contribute to failure, such as: contact pressure, applied stres ses, friction coefficient, displacement amplitude and elastic properti es of both contacting materials. Initial predictions of the suggested expression provide good correlation with test results, and the express ion could thus be adopted as an analytical tool for predicting strengt h under fretting conditions. Copyright (C) 1996 Elsevier Science Ltd