Modelling of Negative Poisson's Ratio Nanomaterials: Deformation Mechanisms, Structure-Property Relationships and Applications

A. Alderson; K.L. Alderson; K.E. Evans; J.N. Grima; M.S. Williams

doi:10.4028/www.scientific.net/JMNM.23.55

Paper Titles

Large Stress Reduction Induced by sp² Clustering in Tetrahedral Amorphous Carbon Films
p.39

Laser Induced Etching for Generation of Si Nanocrystals and Spectroscopic Investigation of Morphology
p.43

Layer Structured Calcium Bismuth Titanate by Mechanical Activation
p.47

Linking Additive Structures to Nanoparticle Properties
p.51

Modelling of Negative Poisson's Ratio Nanomaterials: Deformation Mechanisms, Structure-Property Relationships and Applications
p.55

Nanocrystalline W-Doped SrBi₂Ta₂O₉ of Layered Perovskite Structure Derived from Mechanical Activation
p.59

Nanocrystalline Zirconium Oxide Thin Films Prepared by Filtered Cathodic Vacuum Arc
p.63

On the Wettability of Nanocomposite Amorphous Carbon Films
p.67

Preparation and Characterization of ZnSe/SiO₂ Nanocomposite
p.71

HomeJournal of Metastable and Nanocrystalline...Journal of Metastable and Nanocrystalline...Modelling of Negative Poisson's Ratio...

Modelling of Negative Poisson's Ratio Nanomaterials: Deformation Mechanisms, Structure-Property Relationships and Applications

Abstract:

Analytical and Molecular Mechanics methods have been used to study the deformation mechanisms acting at the molecular level in the auxetic polymorph of crystalline silica (a-cristobalite). The analytical models indicate that a-cristobalite deforms by concurrent tetrahedral dilation and cooperative rotation when stretched along the x3 axis, and that a second phase is predicted to exist for this loading scenario, having a geometry similar to that of ‘idealised’ b-cristobalite. This is supported by preliminary Molecular Mechanics simulations, which also indicate that the cooperative rotation predicted for loading along x3 is not sufficient to describe the deformation mechanism for loading along x1. A negative hydrostatic pressure offset is observed to lead to a change in the sign of the predicted Poisson’s ratio from positive to negative, leading to improved agreement of the Molecular Mechanics model with experiment.