Nicholas Fantuzzi

Abstract:

The mechanical behavior of materials with microstructure, such as particle composites, should consider their discontinuous and heterogeneous nature, because interfaces and/or material phases dominate the mechanical behavior. Non-local description is necessary for problems wherein the structural macroscopic scale is comparable with the local microscopic one (see for instance Trovalusci et al. (2017), Tuna et al. (2020), Tuna and Trovalusci (2020)). Non-classical and non-local continuum descriptions can be carried out by multi-scale approaches via energy equivalence criteria, as presented by Trovalusci and Masiani (1999). In this work, anisotropic materials with irregular hexagonal microstructure are considered. This model is capable of accounting for the particle size and orientation, as well as of the asymmetries in strain and stress occurring as a consequence of anisotropy (Fantuzzi et al. (2019a,b)). The present dynamic model is a suitable enrichment of the study presented by Fantuzzi et al. (2019b) where a composite of hexagonal rigid particles interacting through elastic interfaces was derived in a static context. Some paradigmatic cases are discussed, showing how the orientation of the crystal lattice clearly affects the dynamics at the equivalent continuum scale. The reliability of the proposed multiscale strategy is evaluated comparing the results with those provided by finite element simulations.