Abstract
An overload was applied during a fatigue-crack-growth experiment, resulting in a temporary decrease in crack-growth rates, i.e., a retardation period. Neutron diffraction was used to investigate the retardation phenomenon by mapping the changes in the lattice-strain profiles around the fatigue-crack tip in a series of compact-tension (CT) specimens, which were fatigued to various stages through the retardation period after the overload. Following the overload, compressive-strain fields were observed along the loading direction close to the crack tip. As the crack grows out of the retardation period, the residual compressive strains decreased.
| Original language | English |
|---|---|
| Pages (from-to) | 633-635 |
| Number of pages | 3 |
| Journal | Physica B: Physics of Condensed Matter |
| Volume | 385-386 I |
| DOIs | |
| State | Published - Nov 27 2006 |
Funding
This work is supported by the US National Science Foundation (NSF) International Materials Institutes (IMI) Program under Contract DMR-0231320, with Dr. C. Huber as the program director. Measurements at NRSF2 are sponsored by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of FreedomCAR and Vehicle Technologies, as part of the High Temperature Materials Laboratory User Program, Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy under Contract number DE-AC05-00OR22725.
Keywords
- Crack closure
- Fatigue
- Neutron diffraction