Abstract
•FFF-printed ABS/SiO2 nanocomposites for dynamic fracture studies.•Developed a novel experimental fixture for dynamic fracture studies.•Dynamic KIC of nanocomposite increased by 130% compared to static conditions.•Dynamic mixed-mode fracture envelope of ABS/SiO2 is 10% higher than ABS.•Correlated dynamic fracture toughness with toughening mechanisms.
This study presents an experimental investigation of the dynamic mixed-mode fracture behavior of additively manufactured acrylonitrile butadiene styrene (ABS) and ABS/SiO2 nanocomposites fabricated by fused filament fabrication (FFF). A novel dynamic mixed-mode fracture Arcan fixture integrated with a modified Hopkinson bar system is developed to apply controlled combinations of mode-I and mode-II loading at both low and high loading rates. Three material systems are examined: commercial ABS filament (ABS-C), pellet-extruded ABS (ABS-P), and nanoparticle-reinforced ABS (ABS-NC) containing 3 wt% SiO2.
Results reveal a strong strain-rate dependence of fracture toughness for all materials, with the enhancement being substantially greater for mode-I than for mode-II loading. Compared with quasi-static conditions, the dynamic mode-I fracture toughness of ABS-C and ABS-P increases by approximately 100–120%, while ABS-NC exhibits the largest improvement, approaching 130% due to nanoparticle-induced crack deflection and micro-mechanical toughening. Mode-II fracture toughness also increases with loading rate, but more moderately (35–60%), reflecting the dominant role of interlayer interfaces in shear-controlled fracture.
Normalized mixed-mode fracture envelopes demonstrate that ABS-NC provides the widest safe operating region under both quasi-static and dynamic loading, with an envelope area expansion of approximately 10% higher than that of ABS-P. Fractographic analysis reveals that nanoparticle-mediated crack deflection, micro-void coalescence, ligament bridging, and enhanced interlayer cohesion govern the superior performance of ABS-NC. These findings establish nanoparticle reinforcement as an effective strategy for enhancing the damage tolerance of FFF-printed thermoplastics under complex high-rate loading conditions.