Bending behavior of sandwich structures with flexible functionally graded core based on high-order sandwich panel theory

Meccanica ◽  
2015 ◽  
Vol 51 (5) ◽  
pp. 1093-1112 ◽  
Author(s):  
M. J. Lashkari ◽  
O. Rahmani
Keyword(s):  
Sandwich Panel ◽  
Sandwich Structures ◽  
Functionally Graded ◽  
High Order ◽  
Bending Behavior

Free vibration analysis of sandwich beams with carbon nanotube reinforced face sheets based on extended high-order sandwich panel theory

2016 ◽  
Vol 20 (2) ◽  
pp. 219-248 ◽  
Author(s):  
S Jedari Salami
Keyword(s):  
Carbon Nanotube ◽  
Boundary Conditions ◽  
Sandwich Panel ◽  
Sandwich Beam ◽  
Free Vibration Analysis ◽  
Functionally Graded ◽  
High Order ◽  
Reinforced Composite ◽  
The Face ◽  
Composite Face

Free vibration analysis of a sandwich beam with soft core and carbon nanotube reinforced composite face sheets, hitherto not reported in the literature, based on extended high-order sandwich panel theory is presented. Distribution of fibers through the thickness of the face sheets could be uniform or functionally graded. In this theory, the face sheets follow the first-order shear deformation theory. Besides, the two-dimensional elasticity is used for the core. The field equations are derived via the Ritz-based solution which is suitable for any essential boundary conditions. Chebyshev polynomials multiplying boundary R-functions are used as admissible functions and evidence of their good performance is given. A detailed parametric study is conducted to study the effects of nanotube volume fraction and their distribution pattern, core-to-face sheet thickness ratio, and boundary conditions on the natural frequencies and mode shapes of sandwich beams with functionally graded carbon nanotube reinforced composite face sheets and soft cores. Since the extended high-order sandwich panel theory can be used with any combinations of core and face sheets and not only the soft cores that the other theories demand, the results for the same beam with functionally graded carbon nanotube reinforced composite face sheets and stiff core are also provided for comparison. It is concluded that the sandwich beam with X and V distribution figures of face sheets, no matter what the boundary conditions, has higher vibration performance than the beam with UD-CNTRC face sheets.

Free vibration analysis of micro-magneto-electro-elastic cylindrical sandwich panel considering functionally graded carbon nanotube–reinforced nanocomposite face sheets, various circuit boundary conditions, and temperature-dependent material properties using high-order sandwich panel theory and modified strain gradient theory

2017 ◽  
Vol 29 (5) ◽  
pp. 863-882 ◽  
Author(s):  
M Mohammadimehr ◽  
SM Akhavan Alavi ◽  
SV Okhravi ◽  
SH Edjtahed
Keyword(s):  
Boundary Conditions ◽  
Sandwich Panel ◽  
Free Vibration Analysis ◽  
Functionally Graded ◽  
High Order ◽  
Strain Gradient Theory ◽  
Gradient Theory ◽  
Temperature Dependent ◽  
Modified Strain Gradient Theory ◽  
The Face

In this article, based on high-order sandwich panel theory and modified strain gradient theory, free vibration analysis of a micro-magneto-electro-elastic sandwich panel with a transversely flexible core and functionally graded carbon nanotube–reinforced nanocomposite face sheets is investigated. Also, the influences of temperature-dependent material properties and various circuit boundary conditions such as open and closed are considered in this study. Carbon nanotubes are arranged in longitudinal direction inside polyvinylidene fluoride matrix with various functionally graded (FG) distributions such as uniform, FG-V, FG-A, FG-X, and FG-O in the face sheets. The generalized rule of mixture is employed to predict mechanical, electrical, magnetic, and thermal properties of micro-sandwich composite panel. The classical shell theory and an elasticity high-order theory are used for the face sheets and the core, respectively. Then, the governing equations of motion are derived using Hamilton’s principle. In this article, the influences of the volume fraction, the various distributions of carbon nanotubes, the multi-physical fields, open- and closed-circuit boundary conditions, the material length scale parameters, different face sheet and core thicknesses, and temperature changes on the natural frequency are investigated, and the obtained results show that these influences play an important role in the natural frequencies and can be used in order to prevent the resonance phenomenon and also for manufacturing process design and optimization of micro-magneto-electro-elastic composite sandwich cylindrical panels.

Analytical Solution for Free Vibration of Sandwich Structures with a Functionally Graded Syntactic Foam Core

2010 ◽  
Vol 636-637 ◽  
pp. 1143-1149 ◽  
Author(s):  
O. Rahmani ◽  
K. Malekzadeh ◽  
S. Mohammad ◽  
R. Khalili
Keyword(s):  
Free Vibration ◽  
Sandwich Panel ◽  
Sandwich Structures ◽  
Numerical Study ◽  
Sandwich Beam ◽  
Syntactic Foam ◽  
Beam Theory ◽  
Functionally Graded ◽  
Foam Core ◽  
The Face

In this study, after a brief introduction to recent investigations on syntactic foam, the free vibration of sandwich structures with syntactic foam as a functionally graded flexible core based on higher order sandwich panel theory is investigated. The formulation uses the classical beam theory for the face sheets and an elasticity theory for the functionally graded core. In the following a numerical study of free vibration of a simply-supported sandwich beam is carried out and corresponding eigenmodes are obtained.

scholarly journals A Hybrid High-Order method for Kirchhoff–Love plate bending problems

2018 ◽  
Vol 52 (2) ◽  
pp. 393-421 ◽  
Author(s):  
Francesco Bonaldi ◽  
Daniele A. Di Pietro ◽  
Giuseppe Geymonat ◽  
Françoise Krasucki
Keyword(s):  
Sharp Estimate ◽  
High Order ◽  
Plate Bending ◽  
Mechanical Modeling ◽  
High Order Method ◽  
Local Polynomial ◽  
Bending Behavior ◽  
Bending Problems ◽  
Norm Of The Error ◽  
Theoretical Results

We present a novel Hybrid High-Order (HHO) discretization of fourth-order elliptic problems arising from the mechanical modeling of the bending behavior of Kirchhoff–Love plates, including the biharmonic equation as a particular case. The proposed HHO method supports arbitrary approximation orders on general polygonal meshes, and reproduces the key mechanical equilibrium relations locally inside each element. When polynomials of degree k ≥ 1 are used as unknowns, we prove convergence in hk+1 (with h denoting, as usual, the meshsize) in an energy-like norm. A key ingredient in the proof are novel approximation results for the energy projector on local polynomial spaces. Under biharmonic regularity assumptions, a sharp estimate in hk+3 is also derived for the L2-norm of the error on the deflection. The theoretical results are supported by numerical experiments, which additionally show the robustness of the method with respect to the choice of the stabilization.

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