Influence of Glass Fabric Architecture on Delamination Resistance of GLARE FML

Abstract Fiber–metal laminates (FMLs) combine the advantages of metallic layers and fiber-reinforced composites; however, interlaminar delamination remains a critical failure mechanism limiting their structural reliability. In this study, the Mode-I interlaminar fracture behavior of glass/epoxy/aluminum laminates (GLARE) was experimentally investigated as a function of interfacial fiber architecture, including AL//0, AL//90, AL//plain-woven, and AL//glass-mat configurations. Double Cantilever Beam (DCB) tests were conducted in accordance with ASTM D5528 to evaluate the strain energy release rate and crack propagation characteristics. The results reveal that interfacial architecture plays a dominant role in governing fracture resistance. The AL//90 configuration exhibited the highest propagation toughness (≈ 1645–1720 J/m²), nearly twice that of the AL//0 interface (≈ 611–700 J/m²), despite the presence of significant fiber bridging in the latter. Woven interfaces showed reduced and and glass-mat highly heterogeneous fracture responses due to tow undulation and random fiber distribution, respectively. Fractographic analysis identified distinct crack propagation mechanisms, including fiber pull-out, bridging, and interfacial debonding, which directly correlate with the measured energy-release behavior. A cohesive zone model (CZM) was implemented to simulate delamination initiation and propagation, showing good agreement with the experimental load–displacement responses while capturing the overall fracture trends across different interface configurations. The findings demonstrate that interfacial fiber architecture governs delamination resistance more strongly than bridging effects alone, providing critical insight for the design and optimization of FML structures.