Nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory

This paper is devoted to examining the nonlinear vibrational behaviors of functionally graded (FG) sandwich nanobeams in the presence of initial geometric imperfection. Based on the nonlocal strain gradient theory, the governing equation of the FG sandwich nanobeam with consideration of the Von-Karm...

Full description

Bibliographic Details
Main Authors: Liu, Hu, Lv, Zheng, Wu, Han
Other Authors: School of Mechanical and Aerospace Engineering
Format: Journal Article
Language:English
Published: 2021
Subjects:
Online Access:https://hdl.handle.net/10356/151554
_version_ 1811692330640474112
author Liu, Hu
Lv, Zheng
Wu, Han
author2 School of Mechanical and Aerospace Engineering
author_facet School of Mechanical and Aerospace Engineering
Liu, Hu
Lv, Zheng
Wu, Han
author_sort Liu, Hu
collection NTU
description This paper is devoted to examining the nonlinear vibrational behaviors of functionally graded (FG) sandwich nanobeams in the presence of initial geometric imperfection. Based on the nonlocal strain gradient theory, the governing equation of the FG sandwich nanobeam with consideration of the Von-Karman nonlinearity and initial geometric imperfection is derived. The nonlinear oscillator frequency is obtained with the aid of He's variational principle. Three types of nanobeams, i.e., FG nanobeam (Type A), sandwich nanobeam with homogeneous core and FG skins (Type B), and sandwich nanobeam with FG core and homogeneous skins (Type C) are taken into account. A cosine function similar to the mode shape form is employed to describe the geometric imperfection mode. Firstly, the present theoretical model is verified by comparing with previous perfect FG sandwich beams. Then, several key parameters such as the power-law exponent, the amplitudes of the nonlinear oscillator and the geometric imperfection, as well as the nonlocal and material characteristic parameters are investigated in detail. Finally, apart from the structural types, the influence of thickness distribution scheme is also thoroughly elucidated. The results obtained in this paper are helpful for exploring the FG sandwich design to enhance the mechanical performance of nano-devices.
first_indexed 2024-10-01T06:34:04Z
format Journal Article
id ntu-10356/151554
institution Nanyang Technological University
language English
last_indexed 2024-10-01T06:34:04Z
publishDate 2021
record_format dspace
spelling ntu-10356/1515542021-06-30T02:27:00Z Nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory Liu, Hu Lv, Zheng Wu, Han School of Mechanical and Aerospace Engineering School of Civil and Environmental Engineering Engineering::Mechanical engineering Engineering::Civil engineering Nonlinear Vibration Functionally Graded This paper is devoted to examining the nonlinear vibrational behaviors of functionally graded (FG) sandwich nanobeams in the presence of initial geometric imperfection. Based on the nonlocal strain gradient theory, the governing equation of the FG sandwich nanobeam with consideration of the Von-Karman nonlinearity and initial geometric imperfection is derived. The nonlinear oscillator frequency is obtained with the aid of He's variational principle. Three types of nanobeams, i.e., FG nanobeam (Type A), sandwich nanobeam with homogeneous core and FG skins (Type B), and sandwich nanobeam with FG core and homogeneous skins (Type C) are taken into account. A cosine function similar to the mode shape form is employed to describe the geometric imperfection mode. Firstly, the present theoretical model is verified by comparing with previous perfect FG sandwich beams. Then, several key parameters such as the power-law exponent, the amplitudes of the nonlinear oscillator and the geometric imperfection, as well as the nonlocal and material characteristic parameters are investigated in detail. Finally, apart from the structural types, the influence of thickness distribution scheme is also thoroughly elucidated. The results obtained in this paper are helpful for exploring the FG sandwich design to enhance the mechanical performance of nano-devices. 2021-06-30T02:27:00Z 2021-06-30T02:27:00Z 2019 Journal Article Liu, H., Lv, Z. & Wu, H. (2019). Nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory. Composite Structures, 214, 47-61. https://dx.doi.org/10.1016/j.compstruct.2019.01.090 0263-8223 https://hdl.handle.net/10356/151554 10.1016/j.compstruct.2019.01.090 2-s2.0-85061060738 214 47 61 en Composite Structures © 2019 Elsevier Ltd. All rights reserved.
spellingShingle Engineering::Mechanical engineering
Engineering::Civil engineering
Nonlinear Vibration
Functionally Graded
Liu, Hu
Lv, Zheng
Wu, Han
Nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory
title Nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory
title_full Nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory
title_fullStr Nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory
title_full_unstemmed Nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory
title_short Nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory
title_sort nonlinear free vibration of geometrically imperfect functionally graded sandwich nanobeams based on nonlocal strain gradient theory
topic Engineering::Mechanical engineering
Engineering::Civil engineering
Nonlinear Vibration
Functionally Graded
url https://hdl.handle.net/10356/151554
work_keys_str_mv AT liuhu nonlinearfreevibrationofgeometricallyimperfectfunctionallygradedsandwichnanobeamsbasedonnonlocalstraingradienttheory
AT lvzheng nonlinearfreevibrationofgeometricallyimperfectfunctionallygradedsandwichnanobeamsbasedonnonlocalstraingradienttheory
AT wuhan nonlinearfreevibrationofgeometricallyimperfectfunctionallygradedsandwichnanobeamsbasedonnonlocalstraingradienttheory