Multiscale Mechanical Modeling of CNT Structures

We deal in the present work with the following tasks: - multiscale modelling of hysteresis and strain localisation in nanoparticle lattices endowed with bistable elastic potentials; - mechanical modelling and structural identification of CNT foams and CNT multilayer assemblies. A rational approach to the limiting energies at the mesoscopic scale energies consists of determining the continuum limits of the discrete interaction potentials, which characterize the microscopic response (bistable elastic potentials). We formulate a multiscale mechanical model of CNT structures under compressive loading, which is inspired by some distinctive features of the micromechanical response reported earlier in the literature for such materials (see, e.g., Cao et al., 2005; Hutchens et al., 2010) The given model make uses of multiscale chains of lumped masses connected by nonlinear springs, and captures the characteristic ‘three-phase’ response of the examined structures (a:linear response; b:buckling; c:densification). We show that a series of bistable elastic springs indeed exhibits such a kind of response, and through-the-thickness localisation of the axial deformation, mimicking the snap-buckling events and the macroscopic hysteresis observed in real CNT arrays.