Multi-scale modeling of bending behavior of carbon nanotube-reinforced composites

Carbon nanotubes (CNTs) demonstrate unique mechanical properties with extraordinarily high stiffness, strength and resilience that make them as an ideal reinforcing material for developing new nanocomposites. Due to the current CNT technology limitations, it is difficult to prepare and design new nanocomposites based on experiment approaches which are both expensive and time-consuming. Computational simulation has been recognized as one of powerful tools in overcoming these problems. In this paper, the authors will utilize the multi-scale modeling method to study the bending characteristics of CNT and CNT- reinforced composites. Firstly, a combining molecular dynamics and continuum mechanics based model will be applied on the CNTs, and their tensional and flexural modulus will be obtained through tension and bending simulation analysis. Then the CNT model is simplified to several 3D beams and is inserted into the matrix, thus, a multi-scale RVE (Representative volume element) model of CNT-reinforced composite is established. Using this RVE model, the bending characteristics of CNT-based composites are obtained. The influence of diameter D, length L, aspect ratio L/D, volume fraction, chiral of CNT and shape of RVE as well as the arrangement of CNT in matrix on the reinforcement effect of flexural modulus of resultant nanocomposites will be further discussed.