Interfacial shear behavior of 3D composites reinforced with CNT-grafted carbon fibers

This paper presents the Molecular Dynamic (MD) models and the simulation results for the shear deformation process of an interface representative cell to develop an understanding of the roles of multi-walled carbon nanotube (MWNT) in enhancing fiber-matrix interfacial properties such as shear modulus and strength. Based on the MD results and the two simple formulae of rule of mixture, the shear modulus and strength of the carbon nanotube (CNT) grafted interface can be predicted. It is shown that there exists a good agreement between the predicted fiber-matrix interfacial shear strength with and without grafted CNTs and these measured from single-fiber micro bond test and single-fiber fragmentation test. The MD simulation also shows the MWNTs' shear stress cross-section distribution is similar to that of a circular beam in shear with a non-zero shear stress on the neutral plane.