Deformation and bifurcation analysis of boron-nitride nanotubes

Boron-nitride nanotubes (BNNTs) display unique properties and have many potential applications. An atomistic-based continuum theory is developed for BNNTs. The continuum constitutive model for BNNTs is obtained directly from interatomic potentials for boron and nitrogen. Such an approach involves no additional fitting parameters beyond those introduced in interatomic potentials. The atomistic-based continuum theory is then applied to study the Youngʹs modulus, stress–strain curve and nonlinear bifurcation in BNNTs. It is shown that the mechanical behavior of BNNTs is virtually independent of the diameter and length of BNNTs, but has a strong dependence on helicity.