The Effects of Surface Texture on Fretting Fatigue between Fastener and Aluminum Structure

Multi-fastener lap joints are vulnerable to fretting fatigue when they are subjected to repeated loading. In general the fretting fatigue condition leads to degraded properties of metallic structures due to the presence of the surface stress concentration resulting at the sites of fretting pits. In many cases, fretting can result in premature structure failures therefore a series of counter measures are frequently taken to minimize fretting especially at the fastener holes. One of major factors that affect the fretting phenomena between the fastener and fastener hole is the surface condition of the fasteners.

In this study, the influences of the surface texture and the surface plating of the fastener on the joint life were investigated by conducting double lap shear fatigue testing. It has been found that the joint fretting fatigue resistance is very sensitive to the surface texture of the fastener and as the surface roughness of the fastener is reduced the joint life increases. In addition, the test results presented in this paper indicated that the use of copper plating substantially improves the joint life by reducing the fretting between the fasteners on the aluminum structure.