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.