TENSILE BEHAVIOR EVALUATION OF CARBON NANOTUBE/POLYPROPYLENE COMPOSITES USING NONLINEAR FINITE ELEMENT MODELING

carbon nanotubes (CNTs) are potentially promising fibers for ultra-high-strength
composites. Yet, there are many issues have to be clearly understood to realize the
potential of CNTs in composites. In order to have a better understanding, a multiscale
representative volume element (RYE) for modeling the axial tensile behavior of
polymer matrix containing CNTs is proposed. The finite element model that was
developed consists of CNT, interface and the matrix. An individual CNT was
modeled according to the modified Morse Potential using a frame-like structure with
nonlinear beam elements. The effect of van der Waals forces, crucial in multi-walled
carbon nanotubes (MWCNTs), was modeled using nonlinear spring elements. Stress-strain
response of the simulated CNTs under tension was in excellent agreement with
other atomistic/continuum models. A cohesive zone model was defined to study load
transfer from the surrounding polymer to the CNT.