Abstract
Effect of contact pressure on fretting fatigue life under a given stress amplitude in a high strength steel was studied using bridge-type pads with various span lengths. With an increase in contact pressure, the fretting fatigue life showed a minimum and a maximum when the span length of pad was small. When the span length of pad was large, the life showed only a minimum. These changes in life with contact pressure had no relation to those in tangential force between the pad and the specimen. When the life showed a minimum, the main cracks responsible for failure were initiated at the central portion of the fretted area. This suggested that local stress concentration occurred there.
