Enhancing fracture toughness of laminated composite by chopped-fiber reinforcement

• Main Authors: Singh, Manoj K., Kitey, R.
• Format: Conference Proceeding
• Language: English
• Subjects: Chopped glass fiber; Energy release rate; Fiber bridging and pullout; Mode-I fracture toughness; Reinforced matrix
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2020.12.642

Inter-laminar fracture toughness of glass fiber composites is improved by reinforcing slender fillers into the matrix system. The chopped glass fibers of 16 µm diameter and 600 mm average length are embedded into the epoxy system up to 4% volume fraction. The wet layup technique is employed to fabricate laminates by stacking 16 layers of 450 GSM bidirectional fiber cloth. Double cantilever beam specimens are prepared and ASTM D5528-13 standards are followed to conduct Mode-I fracture tests. While reinforcements show no influence on the crack initiation toughness (GIi) of the laminates, both steady state and maximum energy release rates (GIc and GImax, respectively) are observed to increase with increasing filler volume fraction. The enhancement in fracture characteristics is attributed to the fiber bridging and fiber pullout, occur during crack propagation. Unlike neat epoxy and 2% reinforcement cases, in which the steady-state crack propagation regime is distinct, rapidly falling GI value upon reaching the peak load indicates a catastrophic failure in 4% filler reinforced laminate.