Investigation of variable amplitude loading on fretting fatigue behavior of Ti-6Al-V

The fretting fatigue behavior of Ti-6Al-4V under both constant amplitude and variable amplitude loadings was investigated. Constant amplitude fretting fatigue tests were conducted at a frequency of 200 Hz as well as at 1 Hz, while the variable amplitude loading combined the interaction of these two frequencies. The axial load ratios ranged from nominal values of 0.1 to nominal values of 0.8. Fretting fatigue lives at the higher frequency were found to be less than those from tests conducted at the lower frequency with a larger difference being noted at higher axial load ratios. In general, fretting fatigue resistance for the variable amplitude loading conditions fell within the scatter band of the 200 Hz constant amplitude fretting fatigue tests. Miner's linear damage summation model provided a reasonable, yet slightly unconservative, prediction of the variable amplitude loading tests. (C) 1999 Elsevier Science Ltd. All rights reserved.