Energy Characteristics and Failure Mechanisms for Textile Spread Tow Thin Ply Thermoplastic Composites under Low-velocity Impact

Carbon composites are deemed suitable for components with complex geometries which require high impact resistance. The broad range of industrial applications requires composite structures to be lighter and not to compromise with their mechanical performance. Non-crimp fabrics with lower fibre areal weight (FAW) are the class of reinforcement material which will only bring the advantages of better mechanical properties but will also offer more longevity to the structures and reduced maintenance costs. This research aims at investigating the low-velocity impact performance of textile spread tow thin ply (100 gsm) composites with an aim to study the load bearing capability, deflection characteristics and energy characteristics. The results are compared with the baseline thick (200 gsm) fibre reinforced composites. There was 19.2 %, 16.6 %, and 6.57 % higher peak load for spread tow thin ply composites when compared to thick ply composites at 25 J., 42 J., and 52 J impact energies respectively. Significantly lower residual deflection (40 % to 76 %) and higher major damage energy (20 % to 33 %) were observed for spread tow thin ply laminates compared to the thick ply variant at different impact energies. At 42 J and 52 J impact energies, the damage index (DI) was 2 times and 4 times higher for Thick ply laminates highlighting extensive damage, which is also observed with detailed failure mechanisms study.