Fatigue crack propagation in aluminium alloy foams

被引:74
|
作者
Olurin, OB [1 ]
McCullough, KYG [1 ]
Fleck, NA [1 ]
Ashby, MF [1 ]
机构
[1] Univ Cambridge, Dept Engn, Cambridge CB2 1PZ, England
基金
英国工程与自然科学研究理事会;
关键词
aluminium foams; fatigue crack propagation; small-scale bridging;
D O I
10.1016/S0142-1123(01)00010-X
中图分类号
TH [机械、仪表工业];
学科分类号
0802 ;
摘要
The mode I fatigue crack propagation (FCP) response of the closed-cell aluminium alloy foams Alulight and Alporas have been measured for a relative density in the range 0.1 to 0.4. The validity of linear elastic fracture mechanics (LEFM) to characterise the fatigue crack propagation (FCP) response is demonstrated, and K-increasing and K-decreasing tests are used to determine the full shape of the FCP response. The classical sigmoidal variation of log da/dN with log DeltaK is evident, with a paris-law exponent m=20 for Alulight and m=25 for Alporas. The effects of relative density, mean stress and a single peak overload on the FCP response are investigated. The study concludes by analysing the mechanism of fatigue crack growth; it is suggested that the fatigue crack growth rate is controlled by the progressive degradation of crack bridging by fatigue failure of the cell edges behind the crack tip. (C) 2001 Elsevier Science Ltd. All rights reserved.
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页码:375 / 382
页数:8
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