Multiscale Analysis of Pseudo‐Ductile Tensile Properties of Thin‐Ply Carbon/Glass Hybrid Laminates Based on Microscopic Finite Element Models

ABSTRACT Due to the brittle nature, lightweight fiber‐reinforced composites (FRPs) typically exhibit high strength but low toughness, which to some extent restricts the further application. Based on the previous experimental research on the pseudo‐ductility of carbon/glass (C/G) hybrid laminates with different slit structures, the present study further conducted multi‐scale numerical simulation to explore the micro‐mechanism of pseudo‐ductility formation. The microscopic models revealed that the continuous vertical slits significantly altered the failure mechanism of the central carbon fiber layer and induced a stable delamination phenomenon. For the three discontinuous slit structures, the delamination propagated uniformly from the discontinuous vertical slit end at strain values of 1.97% and 1.64%. When the vertical slits decreased from 20 to 5 mm, the specimens experienced a sudden stress drop when the tensile loading reached the end of the pseudo‐ductility plateau. The microscopic model of discontinuous vertical slits indicated that during the process that the strain increased from 2.36% to 2.53%, the ratio of delamination to interface layer continuously increased to 76%. However, when discontinuous slits formed a small angle (11.3°) with the fiber direction, the specimens exhibited a rapid and localized delamination propagation within the strain range from 2.33% to 2.49%.