Determination of Fatigue Damage.
Abstract
The deformation response of polycrystalline AA2024-T4 to cyclic loading has been determined by conventional and double-crystal diffractometry. These studies show a preferential work-hardening near the surface compared to the bulk. The defect distribution as a function of depth was also investigated as a function of the fraction of fatigue life. From these studies, it was determined that the remaining fatigue life could be predicted by determining the average ratio beta/beta* where beta is the linewidth at any number of fatigue cycles and beta* is the critical linewidth at fracture. Current studies have shown these predictions to be valid for tests where the stress amplitude is held constant for the entire test. A few tests have also been performed where the loading sequence is more complicated. In these tests, the X-ray predictive method was found to be far more accurate than conventional methods. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1980
- Accession Number
- ADA087442
Entities
People
- I. R. Kramer
- R. N. Pangborn
- S. Weissmann
- T. Tsakalakos
- W. E. Mayo