Widespread fatigue damage poses a serious challenge to the design of modern civil aircraft. Tests are conducted to study the fatigue crack growth of 2024-T3 aluminum sheets with multiple collinear holes and cracks. It is observed that due to the interaction between adjacent hole-edge cracks, the fatigue crack growth life of the sheets with multiple collinear cracks is significantly reduced. For the extreme case in this paper, where equal-length cracks emanate from all the holes, the corresponding fatigue crack growth life is about 10% of that of two equal length cracks emanating from a single hole in a finite sheet. The Eshelby's inclusion theory and the weight function method are used to obtain the stress intensity factor of the sheet with multiple collinear holes and cracks. The approximately analytical stress intensity factors are combined with Paris's law for predicting the fatigue crack growth life. For comparison purpose, the finite element method is also used to obtain the stress intensity factor for predicting the fatigue crack growth life. Both the fatigue crack growth lives predicted by using the analytical method and finite element method agree well with the test results. Compared with the finite element method for fatigue crack growth prediction, the method proposed is simpler and more efficient, thus providing a useful tool for fatigue crack growth life prediction of the structure with Multiple Site Damages (MSD).
LI Zhenghong
,
XU Wu
,
ZHANG Xiaojing
,
YU Yin
. Experimental and analytical analyses of fatigue crack growth in sheets with multiple holes and cracks[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2018
, 39(7)
: 221867
-221867
.
DOI: 10.7527/S1000-6893.2018.21867
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