Evaluation of fatigue crack growth behavior of GLARE3 fiber/metal laminates using a compliance method

The objectives of this study were to investigate the effectiveness of a compliance method for analyzing the fatigue crack growth of GLARE3 fiber/metal laminates. The materials tested were GLARE3-5/4 (2.6 mm thick) and GLARE3-3/2 (1.4 mm thick). Centrally notched specimens with two kinds of notch length and two kinds of fiber orientation were fatigue tested under constant amplitude loading. The expression of the experimental stress intensity factor, K exp, for the 2024-T3 aluminum-alloy layers of a GLARE3 is formulated and K exp were obtained from the relationship between crack length and specimen compliance. The test results clarified the following: (1) d a/d N–Δ K exp relationships roughly show the linear relationship independent of the maximum stress level, specimen thickness, notch length, and fiber orientations, (2) the d a/d N–Δ K exp relationships approximately agree with the linear part and its extension of Paris–Erdogan’s law obtained for the d a/d N–Δ K relationship of the 2024-T3 aluminum-alloy, (3) the compliance method is effective for analyzing fatigue crack growth in GLARE3 laminates.