Structural Engineering and Mechanics

Volume 66, Number 3, 2018, pages 369-377

DOI: 10.12989/sem.2018.66.3.369

A unified formulation for modeling of inhomogeneous nonlocal beams

Farzad Ebrahimi and Mohammad Reza Barati

Abstract

In this article, buckling and free vibration of functionally graded (FG) nanobeams resting on elastic foundation are investigated by developing various higher order beam theories which capture shear deformation influences through the thickness of the beam without the need for shear correction factors. The elastic foundation is modeled as linear Winkler springs as well as Pasternak shear layer. The material properties of FG nanobeam are supposed to change gradually along the thickness through the Mori–Tanaka model. The small scale effect is taken into consideration based on nonlocal elasticity theory of Eringen. From Hamilton\'s principle, the nonlocal governing equations of motion are derived and then solved applying analytical solution. To verify the validity of the developed theories, the results of the present work are compared with those available in literature. The effects of shear deformation, elastic foundation, gradient index, nonlocal parameter and slenderness ratio on the buckling and free vibration behavior of FG nanobeams are studied.

Key Words

buckling; dynamic analysis; vibration; nanostructures/nanotubes; functionally graded material; nonlocal elasticity theory

Address

Farzad Ebrahimi: Department of Mechanical Engineering, Faculty of Engineering, Imam Khomeini International University, 3414916818, Qazvin, Iran Mohammad Reza Barati: Aerospace Engineering Department & Center of Excellence in Computational Aerospace, Amirkabir University of Technology, Tehran, Iran