Fatigue Crack Growth Characteristics of a Fiber/Metal Laminate GLARE.

The objective of this study is to investigate the characteristics of fatigue crack growth in a fiber/metal laminate GLARE 3-5/4. This material consists of five 2024-T3 Al alloy thin sheets and four layers of a (0°/90°) glass/epoxy composite. Centrally notched specimens were fatigue tested under constant amplitude loading and crack length was measured using a DC potentialdrop method. The following conclusions were obtained : (1) The scatter in fatigue crack growth lives was a little larger than that of a 2024-T3 Al alloy. (2) The relationship between crack growth rate, da/dN, versus stress intensity factor range, ΔK, obtained on the assumption of a monolithic material was different from that of a single 2024-T3 Al alloy sampled from the GLARE and showed the maximum stress dependence. (3) The relationship between da/dN and ΔKnn, the stress intensity factor range analyzed by Marissen on the basis of a fiber bridging effect, approximately agreed with that of a single 2024-T3 Al alloy specimen regardless of the maximum stress.