High damping and high stiffness CFRP composites with aramid non-woven fabric interlayers

A new kind of structural damping composite was prepared by interleaving aramid non-woven fabrics (ANF) between the carbon fiber reinforced polymer laminates. The composite damping behaviors were experimentally investigated using single cantilever beam vibration test and dynamic mechanical analysis. Meanwhile, the influence of the ANF interlayers on the composite mechanical properties was investigated by measuring the interlaminar shear strength, flexural modulus, flexural strength, compression after impact (CAI), type I interlaminar fracture toughness (GIC) and type II interlaminar fracture toughness (GIIC). It was found that the interleaved ANF layers greatly improved the composite damping properties with an increase as high as 56.3% in the composite loss factor, with a negligible influence on their flexible strength and modulus and interlaminar shear strength. Most importantly, the CAI, GIC and GIIC tests indicated that the composite interlaminar fracture toughness was significantly enhanced by interleaving ANF. Finally, the ANF reinforcing mechanism inside composites was discussed.