21st Congress of International Council of the Aeronautical Sciences, Melbourne, Australia, 13-18 September, 1998
Paper ICAS-98-5.7.5

PREDICTION OF FATIGUE CRACK GROWTH IN FIBER REINFORCED METAL LAMINATES

Guo Y. J., Wu X. R.
Beijing Institute of Aeronautical Materials, PRC

Keywords: fiber reinforced metal laminates, glare, bridging traction, fatigue, crack

Fiber reinforced metal laminates (FRMLs) is a new family of structural materials used in aircraft industry. FRMLs has excellent fatigue performance as a result of the fiber bridging. In order to predict fatigue crack growth in FRMLs, bridging traction distribution along crackline in FRMLs was first determined. Based upon the fatigue mechanisms, a theoretical model for predicting crack growth in FRMLs was developed, and applied to CCT specimens of 211-and 3/2-GLARE. The predicted crack growth rates from the theoretical model were in good agreement with testing results. Based on the experimental observations that crack growth in FRMLs under cyclic loading tends to reach a steady state, a phenomenological model for predicting crack growth in FRMLs was developed. . This phenomenological model requires no knowledge of bridging traction and the delamination growth in FRMLs, thus greatly facilitates engineering applications. The phenomenological model has been exercised on both CCT and SENT specimens of 3/2 GLARE, very good agreement between the predicted lives and test results was found.

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