Dr. Igor Berinskii
School of Mechanical Engineering
Tel Aviv University
Solid mechanics concept is widely accepted to model mechanical properties of materials and systems. However at micro- and nanoscale microstructure plays an essential role and cannot be neglected. Representation of material as a discrete medium gives an opportunity for easy consideration of discontinuous effects. It also helps to determine properties of effective elastic media using the knowledge of microparameters such as geometry of crystal lattice and interatomic interaction. A short review of discrete and structural modeling of some 2D nanomaterials such as graphene and molybdenum disulfide will be presented.
Discrete models can also be used at macroscopic level. A two–parametric mechanical model is proposed to describe a class of auxetic cellular materials. The microstructure of these materials varies from the regular to re–entrant honeycombs with change of the angle between the nodes of material’s lattice. An interaction among the nodes is described by combination of longitudinal and torsional springs. Effective properties of the solid material corresponding to the given microstructure are determined. It is shown that re–entrant honeycomb structures demonstrate the auxetic properties at any combination of parameters whereas the usual honeycombs can have both positive and negative Poisson’s ratios.