An image-driven finite element modeling method for evaluating the stress and strain distribution in carbon nanotubes/epoxy composites

Abstract

Due to the complex morphology of carbon nanotubes (CNTs) in an epoxy resin, it is difficult to establish finite element (FE) models using common methods. Therefore, this study introduces an approach using real TEM images of CNTs/epoxy composites to establish FE models and obtain real stress and strain distributions. Two kinds of multi-walled carbon nanotubes (MWCNTs), unmodified and plasma-treated MWCNTs, were also used to investigate the effects of the dispersion state of MWCNTs on the mechanical properties of MWCNTs/epoxy composites. Due to the real-shape models, the simulation results clearly showed that well-dispersed MWCNTs more effectively transferred stresses, and thus reduced localized stress concentration and improved the deformation resistance in composites. The composite with poorly-dispersed MWCNT exhibited a higher stress concentration at MWCNTs and more severely strained areas in the epoxy resin. In this case, debonding was very likely to occur at the interface of the two substances, and caused the formation of preliminary cracks in the components.