An analysis of rotating bending fretting fatigue tests using bridge specimens

The rotating-bending type of betting fatigue apparatus is analyzed by treating the 'feet' of the bridge as flat pads with rounded corners. This permits a closed-form solution for the contact pressure-indeed, even more complex geometries could be considered, providing the corners are not sharp-and stick/slip zones to be found, allowing for: (a) shearing force, (b) tension within the specimen and (c) tilting of the specimen with respect to the bridge. Example solutions for each of these separate effects are displayed, together with cer tain combinations of effects.