This paper is concerned with the use of the nonlocal Timoshenko beam model for free vibration analysis of single-walled carbon nanotubes (CNTs) including the thermal effect. Unlike the Euler beam model, the Timoshenko beam model allows for the effects of transverse shear deformation and rotary inertia. These effects become significant for CNTs with small length-to-diameter ratios that are normally encountered in applications such as nanoprobes. The elastic Timoshenko beam model is reformulated using the nonlocal differential constitutive relations of Eringen (1972 Int. J. Eng. Sci. 10 1–16). The study focuses on the wave dispersion caused not only by the rotary inertia and the shear deformation in the traditional Timoshenko beam model but also by the nonlocal elasticity characterizing the microstructure of CNTs in a wide frequency range up to terahertz. Numerical results are presented using the nonlocal beam theory to bring out the effect of both the nonlocal parameter and the temperature change on the properties of transverse vibrations of CNTs. The exact nonlocal Timoshenko beam solution presented here should be useful to engineers who are designing microelectromechanical and nanoelectromechanical devices.

No abstract

No abstract

No abstract

In this paper, we present the first principle calculation of the different properties of the full Heusler compounds Cd2LaB, Cd2PrB, and Cd2CeB. Our calculations are based on density functional theory, using the full potential muffin-tin linear orbital method implemented in the LmtART code. For the determination of the exchange and correlation potential, we used the local density approximation and local spin density approximation. The elastic constants are also calculated. The total magnetic moment of Cd2LaB, Cd2PrB, and Cd2CeB using local spin density approximation are 3.334, 3.482, and 3.473 µB at ambient pressure, respectively. We also present the thermal effects using the quasi-harmonic Debye model, in which the vibrations of the network are taken into account. The effects of temperature and pressure on structural parameters, heat capacity, entropy, coefficient of thermal expansion, and the Debye temperatures are determined for unbalanced Gibbs functions.