| タイトル | Fatigue Analyses Under Constant- and Variable-Amplitude Loading Using Small-Crack Theory |
| 本文（外部サイト） | http://hdl.handle.net/2060/19990046065 |
| 著者（英） | Phillips, E. P.; Everett, R. A., Jr.; Newman, J. C., Jr. |
| 著者所属（英） | NASA Langley Research Center|Army Research Lab. |
| 発行日 | 1999-05-01 |
| 言語 | eng |
| 内容記述 | Studies on the growth of small cracks have led to the observation that fatigue life of many engineering materials is primarily "crack growth" from micro-structural features, such as inclusion particles, voids, slip-bands or from manufacturing defects. This paper reviews the capabilities of a plasticity-induced crack-closure model to predict fatigue lives of metallic materials using "small-crack theory" under various loading conditions. Constraint factors, to account for three-dimensional effects, were selected to correlate large-crack growth rate data as a function of the effective stress-intensity factor range (delta-Keff) under constant-amplitude loading. Modifications to the delta-Keff-rate relations in the near-threshold regime were needed to fit measured small-crack growth rate behavior. The model was then used to calculate small-and large-crack growth rates, and to predict total fatigue lives, for notched and un-notched specimens under constant-amplitude and spectrum loading. Fatigue lives were predicted using crack-growth relations and micro-structural features like those that initiated cracks in the fatigue specimens for most of the materials analyzed. Results from the tests and analyses agreed well. |
| NASA分類 | Metallic Materials |
| レポートNO | ARL-TR-2001
NAS 1.15:209329
L-17862
NASA/TM-1999-209329 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/96399 |
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