Nonlinear deformation and progressive failure of multiwalled carbon nanotubes under internal radial pressure

An analytical molecular structural mechanics model has been developed for the nonlinear deformation of multiwalled carbon nanotubes (MWCNTs) under internal radial pressure. Two sources of nonlinearity (i.e., nonlinear in-plane behavior of tube walls and nonlinear van der Waals interactions between layers) are considered. The nonlinear in-plane hoop force resultant-strain relationships of nanotube layers have been derived based on the modified Morse potential, and nonlinear van der Waals interaction has been considered by using the universal graphite potential. Two sets of Morse potential parameters are examined, the effect of van der Waals forces on load transfer between layers in MWCNTs are studied, and the ultimate pressure capacities of MWCNTs under internal pressure have been predicted based on a progressive failure analysis.