Investigation of the impact resistance of carbon nanotube forests within carbon fiber laminated composites through experimental confirmation and finite element substantiation.

Carbon fiber laminated thermoset composites have become the industry standard for applications dictating a high strength-to-weight ratio. However, their brittle nature limits energy dissipation characteristics, often leading to catastrophic failure under low energy impact loadings. In an effort to increase the energy dissipation of these structures, this research examines the potential effects of including in-house synthesized vertically aligned multi-walled carbon nanotube forests within a layered laminate structure using the VARTM technique. Drop tower tests similar to ASTM D7136 are performed on fabricated laminates, including those with alternate insert materials and different resin cures for an added level of evaluation. A linear elastic finite element model with orthotropic properties from micromechanics theory is developed in COMSOL Multiphysics to compare with the experimental tests. Though the nanotube inserts provide some improvement from the base carbon fiber structure, it is anticipated these structures will be more useful as an impact sensor.