Computational elastoplastic structural analysis of carbon nanotubes

Carbon nanotubes represent, in modern application trends, an innovative material with excellent physical characteristics, specifically from a mechanical standpoint. Their growing usage fosters a challenging quest of computational methods suitable for reliable and effective structural analyses [1]. To this aim, modelling approaches capable to deal with nanoscale and atomistic aspects, through classic continuum and structural mechanics methods, turn out to exhibit a particular interest [2,3]. In the present contribution, the carbon-carbon bonds of carbon nanotubes are set to be modelled by beam finite elements, focusing, in particular, on lattice structures for Single-Walled Carbon NanoTubes. Consistently, a first investigation step is devoted to a validation of proposing a constitutive elastoplastic behaviour modelling, with interpretation reference also to experimental data available in the literature. Furthermore, two subsequent structural stages are considered: (a) an evolutive elastoplastic step-by-step analysis, developed according to an algorithm proposed in [4], and (b) a direct, kinematic Limit Analysis collapse study, consistently devised with a numerical implementation as in [5]. The employment of such devoted, self-implemented, computational modelling approaches shall display advantageous features both from a numerical viewpoint and from a practical engineering standpoint. In particular, as discussed by the results of the present contribution, Limit Analysis methodologies are newly proven to constitute effective and robust modelling strategies, toward the assessment of structural and collapse behaviours, also within the context of carbon nanotube structures. References [1] Silvestre, N. (Ed), 2016, Advanced Computational Nanomechanics, Wiley, Chichester. [2] Rafiee, R., Moghadam, R. M., 2014, On the modeling of carbon nanotubes: A critical review, Compos Part B-Eng, 56: 435-449. [3] Li, C., Chou, T.-W., 2003, A structural mechanics approach for the analysis of carbon nanotubes, Int J Solids Struct, 40: 2487-2499. [4] Ferrari, R., Cocchetti, G., Rizzi, E., 2016, Limit Analysis of a historical iron arch bridge. Formulation and computational implementation, Comput Struct, 175: 184-196. [5] Ferrari, R., Cocchetti, G., Rizzi, E., 2018, Effective iterative algorithm for the Limit Analysis of truss-frame structures by a kinematic approach, Comput Struct, 197: 28-41.