The impact of interfacial properties on the macroscopic performance of carbon nanotube composites. A FE2-based multiscale study

Interfacial shear strength (ISS) is known to significantly affect the mechanical performance of carbon-nanotube (CNT) reinforced composites. To illustrate the combined effect of ISS and CNT weight fraction on the behavior of CNT/polymer, a CNT/polymer cantilever beam was analyzed using a three-level multiscale technique. (1) At the atomic level, a short CNT was modeled with a space-frame structure, using modified molecular structural mechanics (mMSM); this structure was approximated by equivalent beam finite elements at the next level. (2) At the microscopic level, a polymer matrix reinforced with a single CNT was analyzed. (3) At the macroscopic level, a cantilever beam was analyzed concurrently at the micro- and macroscopic level using a nested solution scheme and first-order homogenization. The analyses' results showed that increasing the CNT content can improve the damping properties of the composite structure, if ISS is low enough to achieve an optimum extent of microstructural slippage.