Crack initiation and growth behaviour of Al 2024-T4 under fretting fatigue

Abstract

A fretting fatigue experiment is conducted with Al 2024-T4 pad and specimen. A pad has a rectangular foot for simulating punch pressure on the contact surface of the specimen. Fretting fatigue cracks are monitored and analysed by image processing. The crack initiation sites and obliquities are examined. The behaviour of the crack growth rate is also shown. An analysis is carried out along the mid plane of specimen to deal with a plane strain condition. The elastic solution of square punch is utilized to estimate the crack initiation site with assuming the elastic-perfectly plastic behaviour of material. The predictions are in good agreement with the experimental data. The surface traction fields are suggested,from which stress intensity factors are evaluated. Copyright (C) 1997 Elsevier Science Limited.