Prediction of Cold Dwell-Fatigue Crack Growth of Titanium Alloys

Abstract

The dwell effect of the material can reduce the fatigue lives of titanium alloys at room temperature. A unified fatigue life prediction method developed by the authors' group is modified in this paper to predict dwell-fatigue crack growth taking into account the effects of dwell time and maximum stress. The modified model can be successfully used to predict the crack growth rate and calculate the fatigue life of different titanium alloys under pure fatigue and dwell-fatigue conditions. It is validated by comparing prediction results with the experimental data of several titanium alloys with different microstructures, dwell time, hydrogen contents, stress ratios and stress levels.

Micromechanical Analysis of In-Plane Constraint Effect on Local Fracture Behavior of Cracks in the Weakest Locations of Dissimilar Metal Welded Joint

“…This is consistent with the Ref. [34], which showed that the stress is lower in the specimen with high constraint under the same load.…”

Experimental investigation on dwell-fatigue property of Ti–6Al–4V ELI used in deep-sea manned cabin

“…The specific phenomenon of ambient temperature dwell sensitivity of titanium alloy was first recognized in late 1972/early 1973 through the failure of two titanium alloy fan disks in Rolls-Royce RB211 engines which at that time powered Lockheed Tristar aircraft [7,8]. In recent years, creep effect on fatigue in room temperature is more highlighted with the development of advanced measurement technique [9,10], which is often neglected in the past. However, the dwell-fatigue data of Ti-6Al-4V ELI used in the deep-sea manned cabin being constructed in China are not enough for its life evaluation.…”

Three-Dimensional Surface Crack Growth of Maraging Steel Spherical Pressure Shell

“…Ai et al [13] verified the accuracy of the theoretical calculation of fracture mechanics by FRANC3D software and the reliability of crack growth life prediction through calculation examples of embedded elliptical cracks and semi-elliptical surface cracks in thin plates. Wang et al [14] combined ABAQUS and Zencrack software to carry out a numerical simulation analysis of the dwell-fatigue crack growth process, and the simulation results obtained were in good agreement with the test results.…”