Bending and Buckling of Circular Sandwich Plates with the Nonlinear Elastic Core Material

2015 ◽  
Author(s):  
A. Kudin ◽  
◽  
M.A.V. Al-Omari ◽  
B.G.M. Al-Athamneh ◽  
H.K.M. Al-Athamneh
Keyword(s):  
Core Material ◽  
Sandwich Plates ◽  
Elastic Core ◽  
Circular Sandwich Plates ◽  
Nonlinear Elastic

Vibration analysis of a multifunctional hybrid composite honeycomb sandwich plate

2018 ◽  
Vol 22 (8) ◽  
pp. 2818-2860 ◽  
Author(s):  
Paul Praveen A ◽  
Vasudevan Rajamohan ◽  
Ananda Babu Arumugam ◽  
Arun Tom Mathew
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Hybrid Composite ◽  
Sandwich Plate ◽  
Core Material ◽  
Sandwich Plates ◽  
Composite Sandwich ◽  
Honeycomb Sandwich ◽  
Vibration Responses ◽  
Stiffness And Damping

In the present study, the free and forced vibration responses of the composite sandwich plate with carbon nanotube reinforced honeycomb as the core material and laminated composite plates as the top and bottom face sheets are investigated. The governing equations of motion of hybrid composite honeycomb sandwich plates are derived using higher order shear deformation theory and solved numerically using a four-noded rectangular finite element with nine degrees of freedom at each node. Further, various elastic properties of honeycomb core materials with and without reinforcement of carbon nanotube and face materials are evaluated experimentally using the alternative dynamic approach. The effectiveness of the finite element formulation is demonstrated by performing the results evaluated experimentally on a prototype composite sandwich plate with and without carbon nanotube reinforcement in core material. Various parametric studies are performed numerically to study the effects of carbon nanotube wt% in core material, core thickness, ply orientations, and various boundary conditions on the dynamic properties of composite honeycomb sandwich plate. Further, the transverse vibration responses of hybrid composite sandwich plates under harmonic force excitation are analyzed at various wt% of carbon nanotubes and the results are compared with those obtained without addition of carbon nanotubes to demonstrate the effectiveness of carbon nanotube reinforcement in enhancing the stiffness and damping characteristics of the structures. The study provides the guidelines for the designer on enhancing both the stiffness and damping properties of sandwich structures through carbon nanotube reinforcement in core materials.

New Higher-Order Models for Sandwich Plates with a Flexible Core and their Accuracy Assessment

2019 ◽  
Vol 19 (03) ◽  
pp. 1950024 ◽  
Author(s):  
Ali Tian ◽  
Renchuan Ye ◽  
Peng Ren ◽  
Pengming Jiang ◽  
Zengtao Chen ◽  
...  
Keyword(s):  
Dynamic Models ◽  
Accuracy Assessment ◽  
Order Theory ◽  
Higher Order ◽  
Analytical Models ◽  
Core Material ◽  
Sandwich Plates ◽  
Higher Order Theory ◽  
Flexible Core

Two higher-order analytical models based on a new higher-order theory for sandwich plates with flexible cores are developed considering the effect of the core material density and skin-to-core-stiffness-ratio (SCSR). The main difference between the two models is the role of the flexible core in the dynamic response of sandwich plates with cores of different stiffnesses. Firstly, the governing equations of a simply supported sandwich plate with a flexible core are derived based on the two models, and the analytical solutions are determined by using Navier’s approach. Then, the free vibration, static, dynamic bending and stress field characteristics of the sandwich plates with different SCSRs are investigated. The results obtained by the proposed method are compared with other published results. In particular, an accuracy assessment of the present dynamic models is conducted for different SCSRs. Finally, conclusions on the applicability of the proposed method and other theories on sandwich plates with different SCSRs are drawn.

Consideration of Both Extensional and Shear Strain of Core Material in Modal Property Estimation of Sandwich Plates

1995 ◽  
Author(s):  
Byung-Chan Lee ◽  
Kwang-Joon Kim
Keyword(s):  
Shear Strain ◽  
Layer Thickness ◽  
Sandwich Beam ◽  
Base Layer ◽  
Core Material ◽  
Viscoelastic Layer ◽  
Sandwich Plates ◽  
Modal Parameter ◽  
The Core ◽  
Plate Length

Abstract In vibration analysis of sandwich beam/plates, it is often assumed that there occurs shear deformation only, i.e. no extension or compression, in the core viscoelastic layer. Certainly, this assumption may have limitations, for example, with increase of the core thickness or frequency range of vibration. The purpose of this paper is to consider the extentional as well as shear strain of the core for modal parameter estimation of the sandwich plates and to investigate how much error will be caused by neglecting the extension or compression in the core material. Natural frequencies and modal loss factors are estimated for a simply supported square plates under each of the above two assumptions. Nondimensional characteristic equations are formulated and solved for various ratios of the base layer thickness to plate length, core to base layer thickness, and constraining layer to base layer thickness.

Large deflections of circular sandwich plates.

AIAA Journal ◽  
1968 ◽  
Vol 6 (4) ◽  
pp. 721-723 ◽  
Author(s):  
C. V. SMITH
Keyword(s):  
Sandwich Plates ◽  
Large Deflections ◽  
Circular Sandwich Plates

Dynamic Response of a Clamped Circular Sandwich Plate Subject to Shock Loading

2004 ◽  
Vol 71 (5) ◽  
pp. 637-645 ◽  
Author(s):  
X. Qiu ◽  
V. S. Deshpande ◽  
N. A. Fleck
Keyword(s):  
Finite Element ◽  
Shock Loading ◽  
Structural Response ◽  
Sandwich Plates ◽  
Explicit Finite Element ◽  
The Face ◽  
Analytical Formulas ◽  
Shock Resistance ◽  
Low Sensitivity ◽  
Circular Sandwich Plates

An analytical model is developed for the deformation response of clamped circular sandwich plates subjected to shock loading in air and in water. The deformation history is divided into three sequential stages and analytical expressions are derived for the deflection, degree of core compression, and for the overall structural response time. An explicit finite element method is employed to assess the accuracy of the analytical formulas for the simplified case where the effects of fluid-structure interaction are neglected. The sandwich panel response has only a low sensitivity to the magnitude of the core compressive strength and to the degree of strain hardening in the face-sheets. The finite element results confirm the accuracy of the analytical predictions for the rigid ideally plastic sandwich plates. The analytical formulas are employed to determine optimal geometries of the sandwich plates that maximize the shock resistance of the plates for a given mass. The optimization reveals that sandwich plates have a superior shock resistance relative to monolithic plates of the same mass.

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