Hierarchical toughening in Glass/Epoxy Composites: Synergistic effects of fiber texture scale and rubbery nanofiber interleaves on delamination resistance
This study investigates synergistic toughening in glass/epoxy composites through fiber texture scaling (560–2000 µm bundles) and NBR/PCL nanofiber interleaves. Coarser textures inherently increased fracture toughness by 95–100 % via fiber bridging and crack-path tortuosity. Nanofiber integration amplified this effect, with coarse-textured nano-modified composites achieving 125 % higher toughness than non-modified counterparts. Key mechanisms included matrix plastic deformation (microvoid formation), enhanced fiber–matrix adhesion (resin-coated fibers), and crack bifurcation. Rising R-curves confirmed progressive energy dissipation, while sawtooth force–displacement patterns revealed intermittent crack arrest at nanofiber-rich zones. SEM analysis showed a transition from brittle failure (smooth interfaces) in non-modified samples to ductile failure (rough, porous morphologies) in nano-modified systems. The macro-nano synergy enabled simultaneous improvements in fracture resistance (GIC ↑125 %, GIR ↑162 %), peak load (↑48 %), and energy absorption without compromising in-plane properties. These results establish a multi-scale design paradigm for aerospace/automotive composites requiring balanced delamination resistance and structural efficiency.
期刊介绍:
Theoretical and Applied Fracture Mechanics'' aims & scopes have been re-designed to cover both the theoretical, applied, and numerical aspects associated with those cracking related phenomena taking place, at a micro-, meso-, and macroscopic level, in materials/components/structures of any kind.
The journal aims to cover the cracking/mechanical behaviour of materials/components/structures in those situations involving both time-independent and time-dependent system of external forces/moments (such as, for instance, quasi-static, impulsive, impact, blasting, creep, contact, and fatigue loading). Since, under the above circumstances, the mechanical behaviour of cracked materials/components/structures is also affected by the environmental conditions, the journal would consider also those theoretical/experimental research works investigating the effect of external variables such as, for instance, the effect of corrosive environments as well as of high/low-temperature.