Prediction of initiation and total life in fretting fatigue considering kinked cracks

This work proposes a methodology to compute fretting fatigue crack initiation and total life by iterative models calibrated with fatigue stress-strain-life curves. One of the main novelty of such models is the assumption that the crack initiation length is determined by the size of the critical distance. To separate initiation and propagation lives, a numerical approach with finite elements is used. The methodology incorporates not only the multiaxial non-proportional characteristic of the stress field in fretting problems, but also the stress gradient effect. Crack initiation path is obtained by means of the SWT parameter, and to validate it, the analysed results are compared with tests considering a cylindrical-flat configuration (Aluminium 7075-T651 alloy). Most of the life initiation estimates, as well as the total life ones, are within a scatter band of 3.

Automated summary

This paper proposes a method to calculate fretting fatigue crack initiation and total life using iterative models calibrated with fatigue stress-strain-life curves, taking into account multiaxial non-proportional stress fields in fretting problems and stress gradient effects. The crack initiation path is obtained through the SWT parameter, and the analyzed results are validated by comparison with tests for an Aluminium 7075-T651 alloy in a cylindrical-flat configuration.