A micromechanics-based numerical study on the viscoelastic damping in carbon nanotube/polymer nanocomposites

Abstract

The viscoelastic damping behavior of carbon nanotube (CNT)/polymer nanocomposites is investigated using a 3D numerical micromechanical model based on the finite element method (FEM) and a complex modulus approach. This model uniquely considers the collective behavior and interactions of multiple, randomly or directionally aligned CNTs within a representative volume element (RVE). To account for the frictional energy dissipation at the interface, a thin, weakened, and lossy interphase is simulated around the CNTs. The computational framework is validated by comparing its predictions for the elastic, viscoelastic creep, and damping properties with existing experimental data. Furthermore, the model is used to perform a sensitivity analysis, exploring the influence of key nanostructural parameters on the effective loss factor of the nanocomposite. The results show that the effective loss factor is significantly enhanced by increasing the CNT volume fraction, a finding directly linked to the greater presence of the lossy interphase. Damping also increases with a thicker interphase and a higher relative loss factor of the interphase. The CNT aspect ratio is shown to have a notable effect, influencing the maximum damping achievable at a specific volume fraction. Finally, for aligned nanofillers, the study reveals a strong dependency of the directional loss factors on the CNT off-axis angle. © 2025 Elsevier Ltd.