The influence of temperature and stress intensity factor upon the striation spacing and fatigue crack propagation rate of aluminum alloy
Occurrence of the tip extension can be considered a stochastic process but the amount deterministic. Equations correspond to models of (a) the microcrack nucleation at the tip and (b) void nucleation at the tip by vacancy condensation; (a) is found in fairly good agreement with experimental data for...
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Published in: | International journal of fracture Vol. 9; no. 4; pp. 489 - 491 |
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Main Authors: | , |
Format: | Journal Article |
Language: | English |
Published: |
01-12-1973
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Online Access: | Get full text |
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Summary: | Occurrence of the tip extension can be considered a stochastic process but the amount deterministic. Equations correspond to models of (a) the microcrack nucleation at the tip and (b) void nucleation at the tip by vacancy condensation; (a) is found in fairly good agreement with experimental data for 7075-T651. Alternatively, tip extension may be seen as deterministic, definitely extending each cycle, but with the amount determined stochastically as a thermal activation process, say, dislocation dynamics, crack propagation rates being given by equations of type (a) using the dislocation dynamics model of a single slip line and type (b) using the dislocations model of multiple slip lines. The two concepts may concern the lower and higher propagation rates, respectively. For 2024-T3 striation spacings and crack propagation rates presented agree with (a). At high stress intensity factors the apparent activation energy for the striation spacing nearly equals that for crack propagation, indicating the second concept may be valid. 6 ref.--EPAA/AF. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0376-9429 1573-2673 |
DOI: | 10.1007/bf00036333 |