Effect of functionalization of single-wall carbon nanotubes (SWNTs) on the damping characteristics of SWNT-based epoxy composites via multiscale analysis

The influence of carbon nanotube functionalization on damping characteristics of SWNT-based composites is investigated for the first time with a sequential multiscale approach. The process consists of two parts. First, the interfacial shear strength between the functionalized nanotube and the epoxy is calculated by simulating a SWNT pull-out test using the molecular dynamics method. The strength values obtained from atomic simulation are then applied to a micromechanical damping model of a representative unit cell of a SWNT/epoxy composite under cyclic loading. The analysis results indicate that the nanotube functionalization increases the interfacial shear strength. Due to the stick-slip motion at the interfacial surface, the effective loss factor of the epoxy with functionalized nanoropes is sensitive to the applied load/stress. The increased shear strength can either enhance or reduce the damping ability of the composite, depending on the operational load/stress range and nanotube aspect ratio.