Yusuke Kinoshita

Predicting active slip systems in β-Sn from ideal shear resistance

We analyse the ideal shear resistances of 15 nonequivalent slip systems in ?-Sn using first-principles density functional theory. From the ideal shear resistance and Schmids law, the orientation dependence of active slip systems in a ?-Sn single crystal subjected to uniaxial tension is investigated. We find that has the lowest ideal shear resistance among the 15 slip systems. Our calculations indicate that, depending on crystal orientation, uniaxial tension activates seven nonequivalent groups of slip systems. The active slip systems for [1?0?0] and [1?1?0] orientations determined in this study agree with the experimental results.

Energetics of Slip Deformation in Beta-Sn: A First-Principles Study

The generalized stacking fault (GSF) energy surfaces of (110), (101), (121), (001), and(100) planes in -Sn are analyzed using first-principles density functional theory calculations. Fromthe minimum energy paths (MEPs) on the GSF energy surfaces analyzed, energetically preferableslip paths of 13 nonequivalent slip systems in -Sn are investigated. It is found that the MEP of(110)[111]/2, (101)[010], (101)[111]/2, (121)[101], and (121)[111]/2 deviates from the straight linepath and takes a curve line path. The results indicate that perfect dislocations on these five slip systemsdissociate into partial dislocations as in cubic and hexagonal crystals.

Effects of wavenumber and chirality on the axial compressive behavior of wavy carbon nanotubes: a molecular mechanics study

The effects of wavenumber and chirality on the axial compressive behavior and properties of wavy carbon nanotubes (CNTs) with multiple Stone-Wales defects are investigated using molecular mechanics simulations with the adaptive intermolecular reactive empirical bond-order potential. The wavy CNTs are assumed to be point-symmetric with respect to their axial centers. It is found that the wavy CNT models, respectively, exhibit a buckling point and long wavelength buckling mode regardless of the wave numbers and chiralities examined. It is also found that the wavy CNTs have nearly the same buckling stresses as their pristine straight counterparts.

Mechanical Properties of Carbon Nanotubes with One-Dimensional Intramolecular Junction

Mechanical properties of single-walled carbon nanotubes with one-dimensional intramolecular junctions (CNT-IMJs) are investigated using first-principles density functional theory calculations. The influence of Stone-Wales (SW) defects (a pair of five- and seven-membered rings) at a junction on the Youngs modulus, tensile strength and breaking strain of the CNT-IMJs are discussed from the charge density and interatomic distance. Our calculations reveal that deformation concentration on a seven-membered ring causes the decrease in the strength and elongation of the CNT-IMJs. It is found that the tensile strength and breaking strain of the CNT-IMJs depend on the position of SW defects, while the number of SW defects hardly affects them. The applicability of AIREBO classical interatomic potential to simulate tensile deformation in the CNT-IMJs is also discussed.