An inelastic multiple discrete aperities model for the effects of compressive underloads in fatigue crack growth
✍ Scribed by G. A. Kardomateas; R. L. Carlson
- Publisher
- Springer Netherlands
- Year
- 1995
- Tongue
- English
- Weight
- 992 KB
- Volume
- 70
- Category
- Article
- ISSN
- 1573-2673
No coin nor oath required. For personal study only.
✦ Synopsis
As a common practice, the compressive (negative load ratio) excursions are ignored when analyses of fatigue crack growth in metals are conducted. However, recent experimental data on fatigue crack growth with intermittent compressive load excursions have shown that the use of this assumption leads in most cases to nonconservative predictions. This paper presents a model that is capable of explaining the observed behavior, including the 'saturation' of the compressive overload effects, and the increase in the crack growth rate once the initial, positive load ratio profile is resumed, following a compressive excursion. The model is based on the plastic crushing of a single asperity or multiple asperities located on the crack face close to the crack tip and under dominantly plane strain conditions. A comparison of the behavior for one and for two asperities is made. Moreover, the effects of hardness and strain hardening are also examined.