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, Kexp, for the 2024-T3 aluminum-alloy layers of a GLARE3 is formulated and Kexp were obtained from the relationship between crack length and specimen compliance. The test results clarified the following: (1) da/dN–ΔKexp relationships roughly show the linear relationship independent of the maximum stress level, specimen thickness, notch length, and fiber orientations, (2) the da/dN–ΔKexp relationships approximately agree with the linear part and its extension of Paris–Erdogan’s law obtained for the da/dN–ΔK relationship of the 2024-T3 aluminum-alloy, (3) the compliance method is effective for analyzing fatigue crack growth in GLARE3 laminates.