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Residual strength prediction of welded stiffened thin-walled structures made of Al 6156-T4 alloy based on CTOD method
Received date: 2014-02-28
Revised date: 2014-04-24
Online published: 2015-03-31
Supported by
National Natural Science Foundation of China (11272019); Major Program for International Cooperation of National Natural Science Foundation of China (51010006)
In order to ensure that aircraft performance satisfies the damage tolerance design requirements, it is necessary to assess its residual strength. This paper deals with the R-curve and residual strength analysis of welded thin-walled structures for aircraft fuselage applications made of Al 6156-T4 alloy. The experimental results have been used to verify the proposed analysis route for the residual strength prediction. In addition, the crack propagation paths are detected when the crack through the stringer and the crack growth rates are measured in two directions. The residual strength is predicted for one-bay and two-bay thin-walled structure with variety initial crack length using different criteria. The results show that crack branching (into skin and stringer) when crack growing approached to the stringer in a perpendicular form. It is found that the residual strength is underestimated using the net section yield criteria for the residual strength prediction. In particular, the prediction based on SINTAP-FITNET evaluation system using parameters CTOD-δ5 is more accurate than using K curve method.
Key words： residual strength; R-curve; CTOD-δ5; thin-walled structures; welding; aluminum alloy
HAO Yanguang , LIU Jianzhong , GUO Xiang , LIU Hu , SHANG Deguang . Residual strength prediction of welded stiffened thin-walled structures made of Al 6156-T4 alloy based on CTOD method[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2015 , 36(3) : 827 -833 . DOI: 10.7527/S1000-6893.2014.0069
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