Author(s)

G. Segerfrojd, G.-S. Wang and A.F. Blom

Abstract

FRETTING FATIGUE IN MECHANICAL JOINTS: Critical Experiments and Numerical Analyses G. Segerfrqjd*t, G.-S. Wang* and A.F. Blom*t * The Aeronautical Research Institute of Sweden, P.O. Box 11021, SE-161 11 Bromma, email sdg@ffa.se, wgs@ffa.se and abm@ffa.se. f The Royal Institute of Technology, Department of Aeronautics, SE-100 44 Stockholm, Sweden ABSTRACT Two different fatigue initiation mechanisms have been observed in 1 1/2-dogbone joints. Some cracks initiated at the edge of the fastener hole at the location of the maximum stress concentration, as would normally be expected. However, fatigue cracks frequently initiated several mm:s away from the edge of the fastener hole. This anomalous behavior is due to fretting and is particularly prevalent in joints assemled with certain fastener systems. This paper summarizes a part of a larger experimental programme and shows which design parameters, e.g. secondary bending, fastener stiffness, etc., control the two differ

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