LIFE PREDICTION OF TITANIUM AND ALUMINUM ALLOYS UNDER FRETTING FATIGUE CONDITIONS USING VARIOUS CRACK PROPAGATION CRITERIA. PART 2. APPLICATION OF THE TECHNIQUE TO CYLINDRICAL SPECIMENS WITH SEMI-ELLIPTICAL CRACK AND ACCOUNT OF THE RESIDUAL STRESSES

摘要

In order to simulate the operating fretting-fatigue conditions in cylindrical structural components, we have performed experimental studies on fretting fatigue of cylindrical specimens with clamped concave cylindrical pads of bridge type. Using the known solutions for stress intensity factors in the semi-elliptical cracks growing in cylindrical specimens, we predict the kinetics of propagation of fretting-fatigue cracks according to the two-parameter model described in Part 1. A close correlation of calculated and experimental fretting-fatigue life values is observed for AMg6N alloy for varied experimental fretting conditions (contact load, slip amplitude and friction coefficient). For alloy VT9 we have provided approbation of the technique, which takes into account distribution of the residual stresses in the material subsurface during calculation of stress-strain state and life under fretting-fatigue conditions.